From 6bad8aebdd76c32ba729a30ac3475e8b379fb77f Mon Sep 17 00:00:00 2001
From: Alexandre Duret-Lutz <adl@lrde.epita.fr>
Date: Sun, 7 Jan 2018 15:08:32 +0100
Subject: [PATCH] python: remove error recovery checks from the public
 notebooks

* tests/python/_autparserr.ipynb: New files, containing error
checking code from automata-io.ipynb and piperead.ipynb.
* tests/python/automata-io.ipynb: Remove error checks, and pipe
examples from piperead.ipynb.
* tests/python/piperead.ipynb: Delete.
* tests/python/word.ipynb: Move error checking code...
* tests/python/_word.ipynb: ... in this new file.
* doc/org/tut.org, tests/Makefile.am: Adjust.
---
 doc/org/tut.org                |   2 -
 tests/Makefile.am              |   3 +-
 tests/python/_autparserr.ipynb | 400 +++++++++++++++++++++++++
 tests/python/_word.ipynb       | 140 +++++++++
 tests/python/automata-io.ipynb | 523 +++++++++++++++++++++------------
 tests/python/piperead.ipynb    | 499 -------------------------------
 tests/python/word.ipynb        | 262 +++--------------
 7 files changed, 917 insertions(+), 912 deletions(-)
 create mode 100644 tests/python/_autparserr.ipynb
 create mode 100644 tests/python/_word.ipynb
 delete mode 100644 tests/python/piperead.ipynb

diff --git a/doc/org/tut.org b/doc/org/tut.org
index d11352df7..c0b4064c7 100644
--- a/doc/org/tut.org
+++ b/doc/org/tut.org
@@ -58,8 +58,6 @@ real notebooks instead.
 - [[https://spot.lrde.epita.fr/ipynb/automata.html][=automata.ipynb=]] covers translation from formulas to automata,
   automata printing, and some lights transformations
 - [[https://spot.lrde.epita.fr/ipynb/automata-io.html][=automata-io.ipynb=]] shows how to save and read automata from files
-- [[https://spot.lrde.epita.fr/ipynb/piperead.html][=piperead.ipynb=]] shows how to save and read automata output from other
-  commands, using pipes
 - [[https://spot.lrde.epita.fr/ipynb/randaut.html][=randaut.ipynb=]] shows a simple case where the [[file:randaut.org][=randaut=]] commands
   generated random automata, which are displayed in a table before and
   after acceptance simplification
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 948083f12..ed0f6c4bc 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -334,7 +334,6 @@ TESTS_ipython = \
   python/highlighting.ipynb \
   python/ltsmin-dve.ipynb \
   python/ltsmin-pml.ipynb \
-  python/piperead.ipynb \
   python/parity.ipynb \
   python/product.ipynb \
   python/randaut.ipynb \
@@ -348,7 +347,9 @@ TESTS_ipython = \
 # with a _.
 TESTS_python = \
   python/_altscc.ipynb \
+  python/_autparserr.ipynb \
   python/_aux.ipynb \
+  python/_word.ipynb \
   python/accparse2.py \
   python/alarm.py \
   python/alternating.py \
diff --git a/tests/python/_autparserr.ipynb b/tests/python/_autparserr.ipynb
new file mode 100644
index 000000000..2aa9b219f
--- /dev/null
+++ b/tests/python/_autparserr.ipynb
@@ -0,0 +1,400 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "import spot\n",
+    "spot.setup()"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Test syntax errors\n",
+    "------------------"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Overwriting _example.aut\n"
+     ]
+    }
+   ],
+   "source": [
+    "%%file _example.aut\n",
+    "HOA: v1\n",
+    "States: 2\n",
+    "Start: 1\n",
+    "AP: 2 \"a\" \"b\"\n",
+    "acc-name: Buchi\n",
+    "Acceptance: 1 Inf(0)\n",
+    "--BODY--\n",
+    "State: 0 {0}\n",
+    "[t] 1\n",
+    "State: 1\n",
+    "[t] 1\n",
+    "--END--\n",
+    "HOA: v1\n",
+    "States: 2\n",
+    "Start: 1\n",
+    "AP: 2 \"a\" \"b\"\n",
+    "Acceptance: 1 Inf(0)\n",
+    "--BODY--\n",
+    "State: 0 {0}\n",
+    "[a] 3\n",
+    "State: 1\n",
+    "[1] 0\n",
+    "[0&!1] 1\n",
+    "--END--"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "image/svg+xml": [
+       "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\"?>\n",
+       "<!DOCTYPE svg PUBLIC \"-//W3C//DTD SVG 1.1//EN\"\n",
+       " \"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd\">\n",
+       "<!-- Generated by graphviz version 2.38.0 (20140413.2041)\n",
+       " -->\n",
+       "<!-- Title: G Pages: 1 -->\n",
+       "<svg width=\"133pt\" height=\"101pt\"\n",
+       " viewBox=\"0.00 0.00 133.00 101.00\" xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\">\n",
+       "<g id=\"graph0\" class=\"graph\" transform=\"scale(1 1) rotate(0) translate(4 97)\">\n",
+       "<title>G</title>\n",
+       "<polygon fill=\"white\" stroke=\"none\" points=\"-4,4 -4,-97 129,-97 129,4 -4,4\"/>\n",
+       "<!-- I -->\n",
+       "<!-- 1 -->\n",
+       "<g id=\"node2\" class=\"node\"><title>1</title>\n",
+       "<ellipse fill=\"#ffffaa\" stroke=\"black\" cx=\"107\" cy=\"-42\" rx=\"18\" ry=\"18\"/>\n",
+       "<text text-anchor=\"middle\" x=\"107\" y=\"-38.3\" font-family=\"Lato\" font-size=\"14.00\">1</text>\n",
+       "</g>\n",
+       "<!-- I&#45;&gt;1 -->\n",
+       "<g id=\"edge1\" class=\"edge\"><title>I&#45;&gt;1</title>\n",
+       "<path fill=\"none\" stroke=\"black\" d=\"M23.0602,-62.9848C24.6706,-62.5773 58.2688,-54.0766 82.2014,-48.0213\"/>\n",
+       "<polygon fill=\"black\" stroke=\"black\" points=\"89.2724,-46.2323 83.2589,-51.0031 85.8793,-47.0908 82.4862,-47.9493 82.4862,-47.9493 82.4862,-47.9493 85.8793,-47.0908 81.7135,-44.8956 89.2724,-46.2323 89.2724,-46.2323\"/>\n",
+       "</g>\n",
+       "<!-- 1&#45;&gt;1 -->\n",
+       "<g id=\"edge3\" class=\"edge\"><title>1&#45;&gt;1</title>\n",
+       "<path fill=\"none\" stroke=\"black\" d=\"M99.9688,-58.6641C98.4062,-68.625 100.75,-78 107,-78 111.688,-78 114.178,-72.7266 114.471,-65.8876\"/>\n",
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+       "<text text-anchor=\"middle\" x=\"107\" y=\"-81.8\" font-family=\"Lato\" font-size=\"14.00\">1</text>\n",
+       "</g>\n",
+       "<!-- 0 -->\n",
+       "<g id=\"node3\" class=\"node\"><title>0</title>\n",
+       "<ellipse fill=\"#ffffaa\" stroke=\"black\" cx=\"22\" cy=\"-22\" rx=\"18\" ry=\"18\"/>\n",
+       "<ellipse fill=\"none\" stroke=\"black\" cx=\"22\" cy=\"-22\" rx=\"22\" ry=\"22\"/>\n",
+       "<text text-anchor=\"middle\" x=\"22\" y=\"-18.3\" font-family=\"Lato\" font-size=\"14.00\">0</text>\n",
+       "</g>\n",
+       "<!-- 0&#45;&gt;1 -->\n",
+       "<g id=\"edge2\" class=\"edge\"><title>0&#45;&gt;1</title>\n",
+       "<path fill=\"none\" stroke=\"black\" d=\"M43.5169,-26.9438C55.3149,-29.7867 70.1833,-33.3695 82.4561,-36.3268\"/>\n",
+       "<polygon fill=\"black\" stroke=\"black\" points=\"89.3394,-37.9854 81.7962,-39.4079 85.9368,-37.1655 82.5342,-36.3455 82.5342,-36.3455 82.5342,-36.3455 85.9368,-37.1655 83.2721,-33.2832 89.3394,-37.9854 89.3394,-37.9854\"/>\n",
+       "<text text-anchor=\"middle\" x=\"66.5\" y=\"-37.8\" font-family=\"Lato\" font-size=\"14.00\">1</text>\n",
+       "</g>\n",
+       "</g>\n",
+       "</svg>\n"
+      ],
+      "text/plain": [
+       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fbec845de70> >"
+      ]
+     },
+     "metadata": {},
+     "output_type": "display_data"
+    },
+    {
+     "ename": "SyntaxError",
+     "evalue": "\n_example.aut:20.2: syntax error, unexpected identifier\n_example.aut:20.1-3: ignoring this invalid label\n_example.aut:20.5: state number is larger than state count...\n_example.aut:14.1-9: ... declared here.\n (<string>)",
+     "output_type": "error",
+     "traceback": [
+      "\u001b[0;36m  File \u001b[0;32m\"<string>\"\u001b[0;36m, line \u001b[0;32munknown\u001b[0m\n\u001b[0;31mSyntaxError\u001b[0m\u001b[0;31m:\u001b[0m \n_example.aut:20.2: syntax error, unexpected identifier\n_example.aut:20.1-3: ignoring this invalid label\n_example.aut:20.5: state number is larger than state count...\n_example.aut:14.1-9: ... declared here.\n\n"
+     ]
+    }
+   ],
+   "source": [
+    "for a in spot.automata('_example.aut'):\n",
+    "    display(a)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "image/svg+xml": [
+       "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\"?>\n",
+       "<!DOCTYPE svg PUBLIC \"-//W3C//DTD SVG 1.1//EN\"\n",
+       " \"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd\">\n",
+       "<!-- Generated by graphviz version 2.38.0 (20140413.2041)\n",
+       " -->\n",
+       "<!-- Title: G Pages: 1 -->\n",
+       "<svg width=\"133pt\" height=\"101pt\"\n",
+       " viewBox=\"0.00 0.00 133.00 101.00\" xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\">\n",
+       "<g id=\"graph0\" class=\"graph\" transform=\"scale(1 1) rotate(0) translate(4 97)\">\n",
+       "<title>G</title>\n",
+       "<polygon fill=\"white\" stroke=\"none\" points=\"-4,4 -4,-97 129,-97 129,4 -4,4\"/>\n",
+       "<!-- I -->\n",
+       "<!-- 1 -->\n",
+       "<g id=\"node2\" class=\"node\"><title>1</title>\n",
+       "<ellipse fill=\"#ffffaa\" stroke=\"black\" cx=\"107\" cy=\"-42\" rx=\"18\" ry=\"18\"/>\n",
+       "<text text-anchor=\"middle\" x=\"107\" y=\"-38.3\" font-family=\"Lato\" font-size=\"14.00\">1</text>\n",
+       "</g>\n",
+       "<!-- I&#45;&gt;1 -->\n",
+       "<g id=\"edge1\" class=\"edge\"><title>I&#45;&gt;1</title>\n",
+       "<path fill=\"none\" stroke=\"black\" d=\"M23.0602,-62.9848C24.6706,-62.5773 58.2688,-54.0766 82.2014,-48.0213\"/>\n",
+       "<polygon fill=\"black\" stroke=\"black\" points=\"89.2724,-46.2323 83.2589,-51.0031 85.8793,-47.0908 82.4862,-47.9493 82.4862,-47.9493 82.4862,-47.9493 85.8793,-47.0908 81.7135,-44.8956 89.2724,-46.2323 89.2724,-46.2323\"/>\n",
+       "</g>\n",
+       "<!-- 1&#45;&gt;1 -->\n",
+       "<g id=\"edge3\" class=\"edge\"><title>1&#45;&gt;1</title>\n",
+       "<path fill=\"none\" stroke=\"black\" d=\"M99.9688,-58.6641C98.4062,-68.625 100.75,-78 107,-78 111.688,-78 114.178,-72.7266 114.471,-65.8876\"/>\n",
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+       "<text text-anchor=\"middle\" x=\"107\" y=\"-81.8\" font-family=\"Lato\" font-size=\"14.00\">1</text>\n",
+       "</g>\n",
+       "<!-- 0 -->\n",
+       "<g id=\"node3\" class=\"node\"><title>0</title>\n",
+       "<ellipse fill=\"#ffffaa\" stroke=\"black\" cx=\"22\" cy=\"-22\" rx=\"18\" ry=\"18\"/>\n",
+       "<ellipse fill=\"none\" stroke=\"black\" cx=\"22\" cy=\"-22\" rx=\"22\" ry=\"22\"/>\n",
+       "<text text-anchor=\"middle\" x=\"22\" y=\"-18.3\" font-family=\"Lato\" font-size=\"14.00\">0</text>\n",
+       "</g>\n",
+       "<!-- 0&#45;&gt;1 -->\n",
+       "<g id=\"edge2\" class=\"edge\"><title>0&#45;&gt;1</title>\n",
+       "<path fill=\"none\" stroke=\"black\" d=\"M43.5169,-26.9438C55.3149,-29.7867 70.1833,-33.3695 82.4561,-36.3268\"/>\n",
+       "<polygon fill=\"black\" stroke=\"black\" points=\"89.3394,-37.9854 81.7962,-39.4079 85.9368,-37.1655 82.5342,-36.3455 82.5342,-36.3455 82.5342,-36.3455 85.9368,-37.1655 83.2721,-33.2832 89.3394,-37.9854 89.3394,-37.9854\"/>\n",
+       "<text text-anchor=\"middle\" x=\"66.5\" y=\"-37.8\" font-family=\"Lato\" font-size=\"14.00\">1</text>\n",
+       "</g>\n",
+       "</g>\n",
+       "</svg>\n"
+      ],
+      "text/plain": [
+       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fbec846c5a0> >"
+      ]
+     },
+     "execution_count": 4,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "spot.automaton('_example.aut', timeout=100)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Error reading from pipe"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "metadata": {},
+   "outputs": [
+    {
+     "ename": "CalledProcessError",
+     "evalue": "Command 'non-existing-cmd ' returned non-zero exit status 127.",
+     "output_type": "error",
+     "traceback": [
+      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
+      "\u001b[0;31mCalledProcessError\u001b[0m                        Traceback (most recent call last)",
+      "\u001b[0;32m<ipython-input-5-6b4750207d55>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m()\u001b[0m\n\u001b[0;32m----> 1\u001b[0;31m \u001b[0mspot\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mautomaton\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m'non-existing-cmd |'\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
+      "\u001b[0;32m/home/adl/git/spot/python/spot/__init__.py\u001b[0m in \u001b[0;36mautomaton\u001b[0;34m(filename, **kwargs)\u001b[0m\n\u001b[1;32m    479\u001b[0m     See `spot.automata` for a list of supported formats.\"\"\"\n\u001b[1;32m    480\u001b[0m     \u001b[0;32mtry\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 481\u001b[0;31m         \u001b[0;32mreturn\u001b[0m \u001b[0mnext\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mautomata\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mfilename\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0;34m**\u001b[0m\u001b[0mkwargs\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m    482\u001b[0m     \u001b[0;32mexcept\u001b[0m \u001b[0mStopIteration\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    483\u001b[0m         \u001b[0;32mraise\u001b[0m \u001b[0mRuntimeError\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m\"Failed to read automaton from {}\"\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mformat\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mfilename\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
+      "\u001b[0;32m/home/adl/git/spot/python/spot/__init__.py\u001b[0m in \u001b[0;36mautomata\u001b[0;34m(timeout, ignore_abort, trust_hoa, no_sid, debug, *sources)\u001b[0m\n\u001b[1;32m    464\u001b[0m                 \u001b[0;32mdel\u001b[0m \u001b[0mproc\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    465\u001b[0m                 \u001b[0;32mif\u001b[0m \u001b[0mret\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 466\u001b[0;31m                     \u001b[0;32mraise\u001b[0m \u001b[0msubprocess\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mCalledProcessError\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mret\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mfilename\u001b[0m\u001b[0;34m[\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m-\u001b[0m\u001b[0;36m1\u001b[0m\u001b[0;34m]\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m    467\u001b[0m     \u001b[0;31m# deleting o explicitely now prevents Python 3.5 from\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    468\u001b[0m     \u001b[0;31m# reporting the following error: \"<built-in function\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
+      "\u001b[0;31mCalledProcessError\u001b[0m: Command 'non-existing-cmd ' returned non-zero exit status 127."
+     ]
+    }
+   ],
+   "source": [
+    "spot.automaton('non-existing-cmd |')"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {},
+   "outputs": [
+    {
+     "ename": "TimeoutExpired",
+     "evalue": "Command 'sleep 3; cat _example.aut ' timed out after 1 seconds",
+     "output_type": "error",
+     "traceback": [
+      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
+      "\u001b[0;31mTimeoutExpired\u001b[0m                            Traceback (most recent call last)",
+      "\u001b[0;32m<ipython-input-6-e4289051db4c>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m()\u001b[0m\n\u001b[0;32m----> 1\u001b[0;31m \u001b[0mspot\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mautomaton\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m'sleep 3; cat _example.aut |'\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mtimeout\u001b[0m\u001b[0;34m=\u001b[0m\u001b[0;36m1\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
+      "\u001b[0;32m/home/adl/git/spot/python/spot/__init__.py\u001b[0m in \u001b[0;36mautomaton\u001b[0;34m(filename, **kwargs)\u001b[0m\n\u001b[1;32m    479\u001b[0m     See `spot.automata` for a list of supported formats.\"\"\"\n\u001b[1;32m    480\u001b[0m     \u001b[0;32mtry\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 481\u001b[0;31m         \u001b[0;32mreturn\u001b[0m \u001b[0mnext\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mautomata\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mfilename\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0;34m**\u001b[0m\u001b[0mkwargs\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m    482\u001b[0m     \u001b[0;32mexcept\u001b[0m \u001b[0mStopIteration\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    483\u001b[0m         \u001b[0;32mraise\u001b[0m \u001b[0mRuntimeError\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m\"Failed to read automaton from {}\"\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mformat\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mfilename\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
+      "\u001b[0;32m/home/adl/git/spot/python/spot/__init__.py\u001b[0m in \u001b[0;36mautomata\u001b[0;34m(timeout, ignore_abort, trust_hoa, no_sid, debug, *sources)\u001b[0m\n\u001b[1;32m    423\u001b[0m                 \u001b[0;32melse\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    424\u001b[0m                     \u001b[0;32mtry\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 425\u001b[0;31m                         \u001b[0mout\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0merr\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0mproc\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mcommunicate\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mtimeout\u001b[0m\u001b[0;34m=\u001b[0m\u001b[0mtimeout\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m    426\u001b[0m                     \u001b[0;32mexcept\u001b[0m \u001b[0msubprocess\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mTimeoutExpired\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    427\u001b[0m                         \u001b[0;31m# Using subprocess.check_output() with timeout\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
+      "\u001b[0;32m/usr/lib/python3.6/subprocess.py\u001b[0m in \u001b[0;36mcommunicate\u001b[0;34m(self, input, timeout)\u001b[0m\n\u001b[1;32m    841\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    842\u001b[0m             \u001b[0;32mtry\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 843\u001b[0;31m                 \u001b[0mstdout\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mstderr\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0mself\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0m_communicate\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0minput\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mendtime\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mtimeout\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m    844\u001b[0m             \u001b[0;32mfinally\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    845\u001b[0m                 \u001b[0mself\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0m_communication_started\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0;32mTrue\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
+      "\u001b[0;32m/usr/lib/python3.6/subprocess.py\u001b[0m in \u001b[0;36m_communicate\u001b[0;34m(self, input, endtime, orig_timeout)\u001b[0m\n\u001b[1;32m   1513\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m   1514\u001b[0m                     \u001b[0mready\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0mselector\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mselect\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mtimeout\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m-> 1515\u001b[0;31m                     \u001b[0mself\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0m_check_timeout\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mendtime\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0morig_timeout\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m   1516\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m   1517\u001b[0m                     \u001b[0;31m# XXX Rewrite these to use non-blocking I/O on the file\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
+      "\u001b[0;32m/usr/lib/python3.6/subprocess.py\u001b[0m in \u001b[0;36m_check_timeout\u001b[0;34m(self, endtime, orig_timeout)\u001b[0m\n\u001b[1;32m    869\u001b[0m             \u001b[0;32mreturn\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    870\u001b[0m         \u001b[0;32mif\u001b[0m \u001b[0m_time\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m)\u001b[0m \u001b[0;34m>\u001b[0m \u001b[0mendtime\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 871\u001b[0;31m             \u001b[0;32mraise\u001b[0m \u001b[0mTimeoutExpired\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mself\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0margs\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0morig_timeout\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m    872\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    873\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n",
+      "\u001b[0;31mTimeoutExpired\u001b[0m: Command 'sleep 3; cat _example.aut ' timed out after 1 seconds"
+     ]
+    }
+   ],
+   "source": [
+    "spot.automaton('sleep 3; cat _example.aut |', timeout=1)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "image/svg+xml": [
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+      ],
+      "text/plain": [
+       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fbec846c570> >"
+      ]
+     },
+     "metadata": {},
+     "output_type": "display_data"
+    },
+    {
+     "ename": "CalledProcessError",
+     "evalue": "Command 'ltl2tgba \"syntax U U error\"' returned non-zero exit status 2.",
+     "output_type": "error",
+     "traceback": [
+      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
+      "\u001b[0;31mCalledProcessError\u001b[0m                        Traceback (most recent call last)",
+      "\u001b[0;32m<ipython-input-7-cf613d56390d>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m()\u001b[0m\n\u001b[0;32m----> 1\u001b[0;31m \u001b[0;32mfor\u001b[0m \u001b[0ma\u001b[0m \u001b[0;32min\u001b[0m \u001b[0mspot\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mautomata\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m\"ltl2tgba 'a U b'|\"\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0;34m'ltl2tgba \"syntax U U error\"|'\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m      2\u001b[0m     \u001b[0mdisplay\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0ma\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
+      "\u001b[0;32m/home/adl/git/spot/python/spot/__init__.py\u001b[0m in \u001b[0;36mautomata\u001b[0;34m(timeout, ignore_abort, trust_hoa, no_sid, debug, *sources)\u001b[0m\n\u001b[1;32m    464\u001b[0m                 \u001b[0;32mdel\u001b[0m \u001b[0mproc\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    465\u001b[0m                 \u001b[0;32mif\u001b[0m \u001b[0mret\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 466\u001b[0;31m                     \u001b[0;32mraise\u001b[0m \u001b[0msubprocess\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mCalledProcessError\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mret\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mfilename\u001b[0m\u001b[0;34m[\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m-\u001b[0m\u001b[0;36m1\u001b[0m\u001b[0;34m]\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m    467\u001b[0m     \u001b[0;31m# deleting o explicitely now prevents Python 3.5 from\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    468\u001b[0m     \u001b[0;31m# reporting the following error: \"<built-in function\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
+      "\u001b[0;31mCalledProcessError\u001b[0m: Command 'ltl2tgba \"syntax U U error\"' returned non-zero exit status 2."
+     ]
+    }
+   ],
+   "source": [
+    "for a in spot.automata(\"ltl2tgba 'a U b'|\", 'ltl2tgba \"syntax U U error\"|'):\n",
+    "    display(a)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Reading an empty file with `spot.automaton()` is an error."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "metadata": {},
+   "outputs": [
+    {
+     "ename": "RuntimeError",
+     "evalue": "Failed to read automaton from true|",
+     "output_type": "error",
+     "traceback": [
+      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
+      "\u001b[0;31mStopIteration\u001b[0m                             Traceback (most recent call last)",
+      "\u001b[0;32m/home/adl/git/spot/python/spot/__init__.py\u001b[0m in \u001b[0;36mautomaton\u001b[0;34m(filename, **kwargs)\u001b[0m\n\u001b[1;32m    480\u001b[0m     \u001b[0;32mtry\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 481\u001b[0;31m         \u001b[0;32mreturn\u001b[0m \u001b[0mnext\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mautomata\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mfilename\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0;34m**\u001b[0m\u001b[0mkwargs\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m    482\u001b[0m     \u001b[0;32mexcept\u001b[0m \u001b[0mStopIteration\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
+      "\u001b[0;31mStopIteration\u001b[0m: ",
+      "\nDuring handling of the above exception, another exception occurred:\n",
+      "\u001b[0;31mRuntimeError\u001b[0m                              Traceback (most recent call last)",
+      "\u001b[0;32m<ipython-input-8-139f3bb684aa>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m()\u001b[0m\n\u001b[0;32m----> 1\u001b[0;31m \u001b[0mspot\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mautomaton\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m'true|'\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
+      "\u001b[0;32m/home/adl/git/spot/python/spot/__init__.py\u001b[0m in \u001b[0;36mautomaton\u001b[0;34m(filename, **kwargs)\u001b[0m\n\u001b[1;32m    481\u001b[0m         \u001b[0;32mreturn\u001b[0m \u001b[0mnext\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mautomata\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mfilename\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0;34m**\u001b[0m\u001b[0mkwargs\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    482\u001b[0m     \u001b[0;32mexcept\u001b[0m \u001b[0mStopIteration\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 483\u001b[0;31m         \u001b[0;32mraise\u001b[0m \u001b[0mRuntimeError\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m\"Failed to read automaton from {}\"\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mformat\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mfilename\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m    484\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    485\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n",
+      "\u001b[0;31mRuntimeError\u001b[0m: Failed to read automaton from true|"
+     ]
+    }
+   ],
+   "source": [
+    "spot.automaton('true|')"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "!rm _example.aut"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.6.4"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 2
+}
diff --git a/tests/python/_word.ipynb b/tests/python/_word.ipynb
new file mode 100644
index 000000000..213299347
--- /dev/null
+++ b/tests/python/_word.ipynb
@@ -0,0 +1,140 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "import spot\n",
+    "spot.setup()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {},
+   "outputs": [
+    {
+     "ename": "SyntaxError",
+     "evalue": "\n>>> a; b&!a; b\n              ^\nA twa_word must contain a cycle\n (<string>)",
+     "output_type": "error",
+     "traceback": [
+      "\u001b[0;36m  File \u001b[0;32m\"<string>\"\u001b[0;36m, line \u001b[0;32munknown\u001b[0m\n\u001b[0;31mSyntaxError\u001b[0m\u001b[0;31m:\u001b[0m \n>>> a; b&!a; b\n              ^\nA twa_word must contain a cycle\n\n"
+     ]
+    }
+   ],
+   "source": [
+    "print(spot.parse_word('a; b&!a; b'))"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {},
+   "outputs": [
+    {
+     "ename": "SyntaxError",
+     "evalue": "\n>>> a; b; c}\n           ^\nExpected ';' delimiter: '}' stands for ending a cycle\n (<string>)",
+     "output_type": "error",
+     "traceback": [
+      "\u001b[0;36m  File \u001b[0;32m\"<string>\"\u001b[0;36m, line \u001b[0;32munknown\u001b[0m\n\u001b[0;31mSyntaxError\u001b[0m\u001b[0;31m:\u001b[0m \n>>> a; b; c}\n           ^\nExpected ';' delimiter: '}' stands for ending a cycle\n\n"
+     ]
+    }
+   ],
+   "source": [
+    "print(spot.parse_word('a; b; c}'))"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {},
+   "outputs": [
+    {
+     "ename": "SyntaxError",
+     "evalue": "\n>>> a; cycle{}\n             ^\nempty input\n\n (<string>)",
+     "output_type": "error",
+     "traceback": [
+      "\u001b[0;36m  File \u001b[0;32m\"<string>\"\u001b[0;36m, line \u001b[0;32munknown\u001b[0m\n\u001b[0;31mSyntaxError\u001b[0m\u001b[0;31m:\u001b[0m \n>>> a; cycle{}\n             ^\nempty input\n\n\n"
+     ]
+    }
+   ],
+   "source": [
+    "print(spot.parse_word('a; cycle{}'))"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "metadata": {},
+   "outputs": [
+    {
+     "ename": "SyntaxError",
+     "evalue": "\n>>> a; cycle{!a}; a\n                ^\nInput should be finished after cycle\n (<string>)",
+     "output_type": "error",
+     "traceback": [
+      "\u001b[0;36m  File \u001b[0;32m\"<string>\"\u001b[0;36m, line \u001b[0;32munknown\u001b[0m\n\u001b[0;31mSyntaxError\u001b[0m\u001b[0;31m:\u001b[0m \n>>> a; cycle{!a}; a\n                ^\nInput should be finished after cycle\n\n"
+     ]
+    }
+   ],
+   "source": [
+    "print(spot.parse_word('a; cycle{!a}; a'))"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# Creating an empty word is OK...\n",
+    "w = spot.twa_word(spot._bdd_dict)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "metadata": {},
+   "outputs": [
+    {
+     "ename": "RuntimeError",
+     "evalue": "a twa_word may not have an empty cycle",
+     "output_type": "error",
+     "traceback": [
+      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
+      "\u001b[0;31mRuntimeError\u001b[0m                              Traceback (most recent call last)",
+      "\u001b[0;32m<ipython-input-7-9968db49e707>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m()\u001b[0m\n\u001b[1;32m      1\u001b[0m \u001b[0;31m# ... as long as this word is not printed.\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m----> 2\u001b[0;31m \u001b[0mprint\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mw\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
+      "\u001b[0;32m/home/adl/git/spot/python/spot/impl.py\u001b[0m in \u001b[0;36m__str__\u001b[0;34m(self)\u001b[0m\n\u001b[1;32m   4922\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m   4923\u001b[0m     \u001b[0;32mdef\u001b[0m \u001b[0m__str__\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mself\u001b[0m\u001b[0;34m)\u001b[0m \u001b[0;34m->\u001b[0m \u001b[0;34m\"std::string\"\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m-> 4924\u001b[0;31m         \u001b[0;32mreturn\u001b[0m \u001b[0m_impl\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mtwa_word___str__\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mself\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m   4925\u001b[0m \u001b[0mtwa_word_swigregister\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0m_impl\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mtwa_word_swigregister\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m   4926\u001b[0m \u001b[0mtwa_word_swigregister\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mtwa_word\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
+      "\u001b[0;31mRuntimeError\u001b[0m: a twa_word may not have an empty cycle"
+     ]
+    }
+   ],
+   "source": [
+    "# ... as long as this word is not printed.\n",
+    "print(w)"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.6.4"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 2
+}
diff --git a/tests/python/automata-io.ipynb b/tests/python/automata-io.ipynb
index 9304361d0..ea4395d4f 100644
--- a/tests/python/automata-io.ipynb
+++ b/tests/python/automata-io.ipynb
@@ -11,6 +11,20 @@
     "spot.setup()"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Converting automata to strings"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Use `to_str()` to output a string representing the automaton in different formats."
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": 2,
@@ -80,6 +94,20 @@
     "    print(a.to_str(fmt))"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Saving automata to files"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Use `save()` to save the automaton into a file."
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": 3,
@@ -138,7 +166,7 @@
        "</svg>\n"
       ],
       "text/plain": [
-       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f195c050a20> >"
+       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fa1c833b9f0> >"
       ]
      },
      "execution_count": 3,
@@ -189,6 +217,20 @@
     "!cat example.aut"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Reading automata from files"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Use `spot.automata()` to read multiple automata from a file, and `spot.automaton()` to read only one."
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": 5,
@@ -247,7 +289,7 @@
        "</svg>\n"
       ],
       "text/plain": [
-       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f195f3ecab0> >"
+       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fa1c82e10c0> >"
       ]
      },
      "metadata": {},
@@ -306,7 +348,7 @@
        "</svg>\n"
       ],
       "text/plain": [
-       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f195c050960> >"
+       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fa1c82abab0> >"
       ]
      },
      "metadata": {},
@@ -322,8 +364,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "Test `--ABORT--`\n",
-    "----------------"
+    "The `--ABORT--` feature of the HOA format allows discarding the automaton being read and starting over."
    ]
   },
   {
@@ -423,7 +464,7 @@
        "</svg>\n"
       ],
       "text/plain": [
-       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f195c050a50> >"
+       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fa1c82ab870> >"
       ]
      },
      "metadata": {},
@@ -435,6 +476,20 @@
     "    display(a)"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Reading automata from strings"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Instead of passing a filename, you can also pass the contents of a file.  `spot.automata()` and `spot.automaton()` look for the absence of newline to decide if this is a filename or a string containing some actual automaton text."
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": 8,
@@ -493,7 +548,7 @@
        "</svg>\n"
       ],
       "text/plain": [
-       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f195c086120> >"
+       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fa1c82aba50> >"
       ]
      },
      "metadata": {},
@@ -543,7 +598,7 @@
        "</svg>\n"
       ],
       "text/plain": [
-       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f195c050900> >"
+       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fa1c82e10f0> >"
       ]
      },
      "metadata": {},
@@ -584,8 +639,9 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "Test syntax errors\n",
-    "------------------"
+    "# Reading automata output from processes\n",
+    "\n",
+    "If an argument of `spot.automata` ends with `|`, then it is interpreted as a shell command that outputs one automaton or more."
    ]
   },
   {
@@ -594,39 +650,235 @@
    "metadata": {},
    "outputs": [
     {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "Overwriting example.aut\n"
-     ]
+     "data": {
+      "image/svg+xml": [
+       "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\"?>\n",
+       "<!DOCTYPE svg PUBLIC \"-//W3C//DTD SVG 1.1//EN\"\n",
+       " \"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd\">\n",
+       "<!-- Generated by graphviz version 2.38.0 (20140413.2041)\n",
+       " -->\n",
+       "<!-- Title: G Pages: 1 -->\n",
+       "<svg width=\"171pt\" height=\"85pt\"\n",
+       " viewBox=\"0.00 0.00 171.00 85.00\" xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\">\n",
+       "<g id=\"graph0\" class=\"graph\" transform=\"scale(1 1) rotate(0) translate(4 81)\">\n",
+       "<title>G</title>\n",
+       "<polygon fill=\"white\" stroke=\"none\" points=\"-4,4 -4,-81 167,-81 167,4 -4,4\"/>\n",
+       "<!-- I -->\n",
+       "<!-- 0 -->\n",
+       "<g id=\"node2\" class=\"node\"><title>0</title>\n",
+       "<ellipse fill=\"#ffffaa\" stroke=\"black\" cx=\"56\" cy=\"-22\" rx=\"18\" ry=\"18\"/>\n",
+       "<text text-anchor=\"middle\" x=\"56\" y=\"-18.3\" font-family=\"Lato\" font-size=\"14.00\">0</text>\n",
+       "</g>\n",
+       "<!-- I&#45;&gt;0 -->\n",
+       "<g id=\"edge1\" class=\"edge\"><title>I&#45;&gt;0</title>\n",
+       "<path fill=\"none\" stroke=\"black\" d=\"M1.15491,-22C2.79388,-22 17.1543,-22 30.6317,-22\"/>\n",
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+       "</g>\n",
+       "<!-- 0&#45;&gt;0 -->\n",
+       "<g id=\"edge3\" class=\"edge\"><title>0&#45;&gt;0</title>\n",
+       "<path fill=\"none\" stroke=\"black\" d=\"M49.6208,-39.0373C48.3189,-48.8579 50.4453,-58 56,-58 60.166,-58 62.4036,-52.8576 62.7128,-46.1433\"/>\n",
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+       "</g>\n",
+       "<!-- 1 -->\n",
+       "<g id=\"node3\" class=\"node\"><title>1</title>\n",
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+       "<text text-anchor=\"middle\" x=\"141\" y=\"-18.3\" font-family=\"Lato\" font-size=\"14.00\">1</text>\n",
+       "</g>\n",
+       "<!-- 0&#45;&gt;1 -->\n",
+       "<g id=\"edge2\" class=\"edge\"><title>0&#45;&gt;1</title>\n",
+       "<path fill=\"none\" stroke=\"black\" d=\"M74.1977,-22C85.0734,-22 99.3874,-22 111.887,-22\"/>\n",
+       "<polygon fill=\"black\" stroke=\"black\" points=\"118.997,-22 111.997,-25.1501 115.497,-22 111.997,-22.0001 111.997,-22.0001 111.997,-22.0001 115.497,-22 111.997,-18.8501 118.997,-22 118.997,-22\"/>\n",
+       "<text text-anchor=\"start\" x=\"92\" y=\"-25.8\" font-family=\"Lato\" font-size=\"14.00\">b</text>\n",
+       "</g>\n",
+       "<!-- 1&#45;&gt;1 -->\n",
+       "<g id=\"edge4\" class=\"edge\"><title>1&#45;&gt;1</title>\n",
+       "<path fill=\"none\" stroke=\"black\" d=\"M132.994,-42.5808C131.886,-52.8447 134.555,-62 141,-62 145.834,-62 148.544,-56.8502 149.129,-49.9451\"/>\n",
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+       "<text text-anchor=\"middle\" x=\"141\" y=\"-65.8\" font-family=\"Lato\" font-size=\"14.00\">1</text>\n",
+       "</g>\n",
+       "</g>\n",
+       "</svg>\n"
+      ],
+      "text/plain": [
+       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fa1c82ab900> >"
+      ]
+     },
+     "metadata": {},
+     "output_type": "display_data"
+    },
+    {
+     "data": {
+      "image/svg+xml": [
+       "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\"?>\n",
+       "<!DOCTYPE svg PUBLIC \"-//W3C//DTD SVG 1.1//EN\"\n",
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    "source": [
-    "%%file example.aut\n",
-    "HOA: v1\n",
-    "States: 2\n",
-    "Start: 1\n",
-    "AP: 2 \"a\" \"b\"\n",
-    "acc-name: Buchi\n",
-    "Acceptance: 1 Inf(0)\n",
-    "--BODY--\n",
-    "State: 0 {0}\n",
-    "[t] 1\n",
-    "State: 1\n",
-    "[t] 1\n",
-    "--END--\n",
-    "HOA: v1\n",
-    "States: 2\n",
-    "Start: 1\n",
-    "AP: 2 \"a\" \"b\"\n",
-    "Acceptance: 1 Inf(0)\n",
-    "--BODY--\n",
-    "State: 0 {0}\n",
-    "[a] 3\n",
-    "State: 1\n",
-    "[1] 0\n",
-    "[0&!1] 1\n",
-    "--END--"
+    "for a in spot.automata('ltl2tgba -s \"a U b\"; ltl2tgba --lbtt \"b\"|', 'ltl2tgba -H \"GFa\" \"a & GFb\"|'):\n",
+    "    display(a)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "A single automaton can be read using `spot.automaton()`, with the same convention."
    ]
   },
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-     "output_type": "error",
-     "traceback": [
-      "\u001b[0;36m  File \u001b[0;32m\"<string>\"\u001b[0;36m, line \u001b[0;32munknown\u001b[0m\n\u001b[0;31mSyntaxError\u001b[0m\u001b[0;31m:\u001b[0m \nexample.aut:20.2: syntax error, unexpected identifier\nexample.aut:20.1-3: ignoring this invalid label\nexample.aut:20.5: state number is larger than state count...\nexample.aut:14.1-9: ... declared here.\n\n"
-     ]
-    }
-   ],
-   "source": [
-    "for a in spot.automata('example.aut'):\n",
-    "    display(a)"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 11,
-   "metadata": {},
-   "outputs": [
-    {
-     "data": {
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-      "text/plain": [
-       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f195c086600> >"
-      ]
-     },
-     "execution_count": 11,
+     "execution_count": 10,
      "metadata": {},
      "output_type": "execute_result"
     }
    ],
    "source": [
-    "spot.automaton('example.aut', timeout=100)"
+    "spot.automaton('ltl2tgba -s6 \"a U b\"|')"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 12,
-   "metadata": {},
-   "outputs": [
-    {
-     "ename": "CalledProcessError",
-     "evalue": "Command 'non-existing-cmd ' returned non-zero exit status 127.",
-     "output_type": "error",
-     "traceback": [
-      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
-      "\u001b[0;31mCalledProcessError\u001b[0m                        Traceback (most recent call last)",
-      "\u001b[0;32m<ipython-input-12-6b4750207d55>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m()\u001b[0m\n\u001b[0;32m----> 1\u001b[0;31m \u001b[0mspot\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mautomaton\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m'non-existing-cmd |'\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
-      "\u001b[0;32m/home/adl/git/spot/python/spot/__init__.py\u001b[0m in \u001b[0;36mautomaton\u001b[0;34m(filename, **kwargs)\u001b[0m\n\u001b[1;32m    479\u001b[0m     See `spot.automata` for a list of supported formats.\"\"\"\n\u001b[1;32m    480\u001b[0m     \u001b[0;32mtry\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 481\u001b[0;31m         \u001b[0;32mreturn\u001b[0m \u001b[0mnext\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mautomata\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mfilename\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0;34m**\u001b[0m\u001b[0mkwargs\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m    482\u001b[0m     \u001b[0;32mexcept\u001b[0m \u001b[0mStopIteration\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    483\u001b[0m         \u001b[0;32mraise\u001b[0m \u001b[0mRuntimeError\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m\"Failed to read automaton from {}\"\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mformat\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mfilename\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
-      "\u001b[0;32m/home/adl/git/spot/python/spot/__init__.py\u001b[0m in \u001b[0;36mautomata\u001b[0;34m(timeout, ignore_abort, trust_hoa, no_sid, debug, *sources)\u001b[0m\n\u001b[1;32m    464\u001b[0m                 \u001b[0;32mdel\u001b[0m \u001b[0mproc\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    465\u001b[0m                 \u001b[0;32mif\u001b[0m \u001b[0mret\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 466\u001b[0;31m                     \u001b[0;32mraise\u001b[0m \u001b[0msubprocess\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mCalledProcessError\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mret\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mfilename\u001b[0m\u001b[0;34m[\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m-\u001b[0m\u001b[0;36m1\u001b[0m\u001b[0;34m]\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m    467\u001b[0m     \u001b[0;31m# deleting o explicitely now prevents Python 3.5 from\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    468\u001b[0m     \u001b[0;31m# reporting the following error: \"<built-in function\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
-      "\u001b[0;31mCalledProcessError\u001b[0m: Command 'non-existing-cmd ' returned non-zero exit status 127."
-     ]
-    }
-   ],
-   "source": [
-    "spot.automaton('non-existing-cmd |')"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 13,
-   "metadata": {},
-   "outputs": [
-    {
-     "ename": "TimeoutExpired",
-     "evalue": "Command 'sleep 3; cat example.aut ' timed out after 1 seconds",
-     "output_type": "error",
-     "traceback": [
-      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
-      "\u001b[0;31mTimeoutExpired\u001b[0m                            Traceback (most recent call last)",
-      "\u001b[0;32m<ipython-input-13-782317e02e1a>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m()\u001b[0m\n\u001b[0;32m----> 1\u001b[0;31m \u001b[0mspot\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mautomaton\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m'sleep 3; cat example.aut |'\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mtimeout\u001b[0m\u001b[0;34m=\u001b[0m\u001b[0;36m1\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
-      "\u001b[0;32m/home/adl/git/spot/python/spot/__init__.py\u001b[0m in \u001b[0;36mautomaton\u001b[0;34m(filename, **kwargs)\u001b[0m\n\u001b[1;32m    479\u001b[0m     See `spot.automata` for a list of supported formats.\"\"\"\n\u001b[1;32m    480\u001b[0m     \u001b[0;32mtry\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 481\u001b[0;31m         \u001b[0;32mreturn\u001b[0m \u001b[0mnext\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mautomata\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mfilename\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0;34m**\u001b[0m\u001b[0mkwargs\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m    482\u001b[0m     \u001b[0;32mexcept\u001b[0m \u001b[0mStopIteration\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    483\u001b[0m         \u001b[0;32mraise\u001b[0m \u001b[0mRuntimeError\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m\"Failed to read automaton from {}\"\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mformat\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mfilename\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
-      "\u001b[0;32m/home/adl/git/spot/python/spot/__init__.py\u001b[0m in \u001b[0;36mautomata\u001b[0;34m(timeout, ignore_abort, trust_hoa, no_sid, debug, *sources)\u001b[0m\n\u001b[1;32m    423\u001b[0m                 \u001b[0;32melse\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    424\u001b[0m                     \u001b[0;32mtry\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 425\u001b[0;31m                         \u001b[0mout\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0merr\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0mproc\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mcommunicate\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mtimeout\u001b[0m\u001b[0;34m=\u001b[0m\u001b[0mtimeout\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m    426\u001b[0m                     \u001b[0;32mexcept\u001b[0m \u001b[0msubprocess\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mTimeoutExpired\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    427\u001b[0m                         \u001b[0;31m# Using subprocess.check_output() with timeout\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
-      "\u001b[0;32m/usr/lib/python3.6/subprocess.py\u001b[0m in \u001b[0;36mcommunicate\u001b[0;34m(self, input, timeout)\u001b[0m\n\u001b[1;32m    841\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    842\u001b[0m             \u001b[0;32mtry\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 843\u001b[0;31m                 \u001b[0mstdout\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mstderr\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0mself\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0m_communicate\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0minput\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mendtime\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mtimeout\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m    844\u001b[0m             \u001b[0;32mfinally\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    845\u001b[0m                 \u001b[0mself\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0m_communication_started\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0;32mTrue\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
-      "\u001b[0;32m/usr/lib/python3.6/subprocess.py\u001b[0m in \u001b[0;36m_communicate\u001b[0;34m(self, input, endtime, orig_timeout)\u001b[0m\n\u001b[1;32m   1513\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m   1514\u001b[0m                     \u001b[0mready\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0mselector\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mselect\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mtimeout\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m-> 1515\u001b[0;31m                     \u001b[0mself\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0m_check_timeout\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mendtime\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0morig_timeout\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m   1516\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m   1517\u001b[0m                     \u001b[0;31m# XXX Rewrite these to use non-blocking I/O on the file\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
-      "\u001b[0;32m/usr/lib/python3.6/subprocess.py\u001b[0m in \u001b[0;36m_check_timeout\u001b[0;34m(self, endtime, orig_timeout)\u001b[0m\n\u001b[1;32m    869\u001b[0m             \u001b[0;32mreturn\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    870\u001b[0m         \u001b[0;32mif\u001b[0m \u001b[0m_time\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m)\u001b[0m \u001b[0;34m>\u001b[0m \u001b[0mendtime\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 871\u001b[0;31m             \u001b[0;32mraise\u001b[0m \u001b[0mTimeoutExpired\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mself\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0margs\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0morig_timeout\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m    872\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    873\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n",
-      "\u001b[0;31mTimeoutExpired\u001b[0m: Command 'sleep 3; cat example.aut ' timed out after 1 seconds"
-     ]
-    }
-   ],
-   "source": [
-    "spot.automaton('sleep 3; cat example.aut |', timeout=1)"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 14,
+   "execution_count": null,
    "metadata": {},
    "outputs": [],
    "source": [
-    "rm example.aut"
+    "!rm example.aut"
    ]
   }
  ],
diff --git a/tests/python/piperead.ipynb b/tests/python/piperead.ipynb
deleted file mode 100644
index 6e9b6db75..000000000
--- a/tests/python/piperead.ipynb
+++ /dev/null
@@ -1,499 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "code",
-   "execution_count": 1,
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "from IPython.display import display \n",
-    "import spot\n",
-    "spot.setup()"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Reading automata output from processes\n",
-    "\n",
-    "If an argument of `spot.automata` ends with `|`, then it is interpreted as a shell command that outputs one automaton or more."
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 2,
-   "metadata": {},
-   "outputs": [
-    {
-     "data": {
-      "image/svg+xml": [
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-    "for a in spot.automata('ltl2tgba -s \"a U b\"; ltl2tgba --lbtt \"b\"|', 'ltl2tgba -H \"GFa\" \"a & GFb\"|'):\n",
-    "    display(a)"
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-    "A single automaton can be read using `spot.automaton()`, with the same convention."
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-       "</svg>\n"
-      ],
-      "text/plain": [
-       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fbd004afa20> >"
-      ]
-     },
-     "execution_count": 3,
-     "metadata": {},
-     "output_type": "execute_result"
-    }
-   ],
-   "source": [
-    "spot.automaton('ltl2tgba -s6 \"a U b\"|')"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Error handling\n",
-    "\n",
-    "If the shell command terminates with a non-zero exit status, we should get an exception."
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 4,
-   "metadata": {},
-   "outputs": [
-    {
-     "ename": "CalledProcessError",
-     "evalue": "Command 'non-existing-command' returned non-zero exit status 127.",
-     "output_type": "error",
-     "traceback": [
-      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
-      "\u001b[0;31mCalledProcessError\u001b[0m                        Traceback (most recent call last)",
-      "\u001b[0;32m<ipython-input-4-8ae92920faed>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m()\u001b[0m\n\u001b[0;32m----> 1\u001b[0;31m \u001b[0mspot\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mautomaton\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m'non-existing-command|'\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
-      "\u001b[0;32m/home/adl/git/spot/python/spot/__init__.py\u001b[0m in \u001b[0;36mautomaton\u001b[0;34m(filename, **kwargs)\u001b[0m\n\u001b[1;32m    479\u001b[0m     See `spot.automata` for a list of supported formats.\"\"\"\n\u001b[1;32m    480\u001b[0m     \u001b[0;32mtry\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 481\u001b[0;31m         \u001b[0;32mreturn\u001b[0m \u001b[0mnext\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mautomata\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mfilename\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0;34m**\u001b[0m\u001b[0mkwargs\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m    482\u001b[0m     \u001b[0;32mexcept\u001b[0m \u001b[0mStopIteration\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    483\u001b[0m         \u001b[0;32mraise\u001b[0m \u001b[0mRuntimeError\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m\"Failed to read automaton from {}\"\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mformat\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mfilename\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
-      "\u001b[0;32m/home/adl/git/spot/python/spot/__init__.py\u001b[0m in \u001b[0;36mautomata\u001b[0;34m(timeout, ignore_abort, trust_hoa, no_sid, debug, *sources)\u001b[0m\n\u001b[1;32m    464\u001b[0m                 \u001b[0;32mdel\u001b[0m \u001b[0mproc\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    465\u001b[0m                 \u001b[0;32mif\u001b[0m \u001b[0mret\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 466\u001b[0;31m                     \u001b[0;32mraise\u001b[0m \u001b[0msubprocess\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mCalledProcessError\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mret\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mfilename\u001b[0m\u001b[0;34m[\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m-\u001b[0m\u001b[0;36m1\u001b[0m\u001b[0;34m]\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m    467\u001b[0m     \u001b[0;31m# deleting o explicitely now prevents Python 3.5 from\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    468\u001b[0m     \u001b[0;31m# reporting the following error: \"<built-in function\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
-      "\u001b[0;31mCalledProcessError\u001b[0m: Command 'non-existing-command' returned non-zero exit status 127."
-     ]
-    }
-   ],
-   "source": [
-    "spot.automaton('non-existing-command|')"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 5,
-   "metadata": {},
-   "outputs": [
-    {
-     "data": {
-      "image/svg+xml": [
-       "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\"?>\n",
-       "<!DOCTYPE svg PUBLIC \"-//W3C//DTD SVG 1.1//EN\"\n",
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-       " viewBox=\"0.00 0.00 171.00 85.00\" xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\">\n",
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-       "<!-- 1 -->\n",
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-       "<text text-anchor=\"middle\" x=\"56\" y=\"-18.3\" font-family=\"Lato\" font-size=\"14.00\">1</text>\n",
-       "</g>\n",
-       "<!-- I&#45;&gt;1 -->\n",
-       "<g id=\"edge1\" class=\"edge\"><title>I&#45;&gt;1</title>\n",
-       "<path fill=\"none\" stroke=\"black\" d=\"M1.15491,-22C2.79388,-22 17.1543,-22 30.6317,-22\"/>\n",
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-       "<!-- 1&#45;&gt;1 -->\n",
-       "<g id=\"edge4\" class=\"edge\"><title>1&#45;&gt;1</title>\n",
-       "<path fill=\"none\" stroke=\"black\" d=\"M49.6208,-39.0373C48.3189,-48.8579 50.4453,-58 56,-58 60.166,-58 62.4036,-52.8576 62.7128,-46.1433\"/>\n",
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-       "<text text-anchor=\"start\" x=\"37.5\" y=\"-61.8\" font-family=\"Lato\" font-size=\"14.00\">a &amp; !b</text>\n",
-       "</g>\n",
-       "<!-- 0 -->\n",
-       "<g id=\"node3\" class=\"node\"><title>0</title>\n",
-       "<ellipse fill=\"#ffffaa\" stroke=\"black\" cx=\"141\" cy=\"-22\" rx=\"18\" ry=\"18\"/>\n",
-       "<ellipse fill=\"none\" stroke=\"black\" cx=\"141\" cy=\"-22\" rx=\"22\" ry=\"22\"/>\n",
-       "<text text-anchor=\"middle\" x=\"141\" y=\"-18.3\" font-family=\"Lato\" font-size=\"14.00\">0</text>\n",
-       "</g>\n",
-       "<!-- 1&#45;&gt;0 -->\n",
-       "<g id=\"edge3\" class=\"edge\"><title>1&#45;&gt;0</title>\n",
-       "<path fill=\"none\" stroke=\"black\" d=\"M74.1977,-22C85.0734,-22 99.3874,-22 111.887,-22\"/>\n",
-       "<polygon fill=\"black\" stroke=\"black\" points=\"118.997,-22 111.997,-25.1501 115.497,-22 111.997,-22.0001 111.997,-22.0001 111.997,-22.0001 115.497,-22 111.997,-18.8501 118.997,-22 118.997,-22\"/>\n",
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-       "</g>\n",
-       "<!-- 0&#45;&gt;0 -->\n",
-       "<g id=\"edge2\" class=\"edge\"><title>0&#45;&gt;0</title>\n",
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-       "</g>\n",
-       "</g>\n",
-       "</svg>\n"
-      ],
-      "text/plain": [
-       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fbd004af8d0> >"
-      ]
-     },
-     "metadata": {},
-     "output_type": "display_data"
-    },
-    {
-     "ename": "CalledProcessError",
-     "evalue": "Command 'ltl2tgba \"syntax U U error\"' returned non-zero exit status 2.",
-     "output_type": "error",
-     "traceback": [
-      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
-      "\u001b[0;31mCalledProcessError\u001b[0m                        Traceback (most recent call last)",
-      "\u001b[0;32m<ipython-input-5-cf613d56390d>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m()\u001b[0m\n\u001b[0;32m----> 1\u001b[0;31m \u001b[0;32mfor\u001b[0m \u001b[0ma\u001b[0m \u001b[0;32min\u001b[0m \u001b[0mspot\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mautomata\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m\"ltl2tgba 'a U b'|\"\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0;34m'ltl2tgba \"syntax U U error\"|'\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m      2\u001b[0m     \u001b[0mdisplay\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0ma\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
-      "\u001b[0;32m/home/adl/git/spot/python/spot/__init__.py\u001b[0m in \u001b[0;36mautomata\u001b[0;34m(timeout, ignore_abort, trust_hoa, no_sid, debug, *sources)\u001b[0m\n\u001b[1;32m    464\u001b[0m                 \u001b[0;32mdel\u001b[0m \u001b[0mproc\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    465\u001b[0m                 \u001b[0;32mif\u001b[0m \u001b[0mret\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 466\u001b[0;31m                     \u001b[0;32mraise\u001b[0m \u001b[0msubprocess\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mCalledProcessError\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mret\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mfilename\u001b[0m\u001b[0;34m[\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m-\u001b[0m\u001b[0;36m1\u001b[0m\u001b[0;34m]\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m    467\u001b[0m     \u001b[0;31m# deleting o explicitely now prevents Python 3.5 from\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    468\u001b[0m     \u001b[0;31m# reporting the following error: \"<built-in function\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
-      "\u001b[0;31mCalledProcessError\u001b[0m: Command 'ltl2tgba \"syntax U U error\"' returned non-zero exit status 2."
-     ]
-    }
-   ],
-   "source": [
-    "for a in spot.automata(\"ltl2tgba 'a U b'|\", 'ltl2tgba \"syntax U U error\"|'):\n",
-    "    display(a)"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "Reading an empty file with `spot.automaton()` is an error."
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 6,
-   "metadata": {},
-   "outputs": [
-    {
-     "ename": "RuntimeError",
-     "evalue": "Failed to read automaton from true|",
-     "output_type": "error",
-     "traceback": [
-      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
-      "\u001b[0;31mStopIteration\u001b[0m                             Traceback (most recent call last)",
-      "\u001b[0;32m/home/adl/git/spot/python/spot/__init__.py\u001b[0m in \u001b[0;36mautomaton\u001b[0;34m(filename, **kwargs)\u001b[0m\n\u001b[1;32m    480\u001b[0m     \u001b[0;32mtry\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 481\u001b[0;31m         \u001b[0;32mreturn\u001b[0m \u001b[0mnext\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mautomata\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mfilename\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0;34m**\u001b[0m\u001b[0mkwargs\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m    482\u001b[0m     \u001b[0;32mexcept\u001b[0m \u001b[0mStopIteration\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
-      "\u001b[0;31mStopIteration\u001b[0m: ",
-      "\nDuring handling of the above exception, another exception occurred:\n",
-      "\u001b[0;31mRuntimeError\u001b[0m                              Traceback (most recent call last)",
-      "\u001b[0;32m<ipython-input-6-139f3bb684aa>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m()\u001b[0m\n\u001b[0;32m----> 1\u001b[0;31m \u001b[0mspot\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mautomaton\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m'true|'\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
-      "\u001b[0;32m/home/adl/git/spot/python/spot/__init__.py\u001b[0m in \u001b[0;36mautomaton\u001b[0;34m(filename, **kwargs)\u001b[0m\n\u001b[1;32m    481\u001b[0m         \u001b[0;32mreturn\u001b[0m \u001b[0mnext\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mautomata\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mfilename\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0;34m**\u001b[0m\u001b[0mkwargs\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    482\u001b[0m     \u001b[0;32mexcept\u001b[0m \u001b[0mStopIteration\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 483\u001b[0;31m         \u001b[0;32mraise\u001b[0m \u001b[0mRuntimeError\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m\"Failed to read automaton from {}\"\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mformat\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mfilename\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m    484\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    485\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n",
-      "\u001b[0;31mRuntimeError\u001b[0m: Failed to read automaton from true|"
-     ]
-    }
-   ],
-   "source": [
-    "spot.automaton('true|')"
-   ]
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 3",
-   "language": "python",
-   "name": "python3"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 3
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython3",
-   "version": "3.6.4"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 2
-}
diff --git a/tests/python/word.ipynb b/tests/python/word.ipynb
index d52e54964..6d6bc28ee 100644
--- a/tests/python/word.ipynb
+++ b/tests/python/word.ipynb
@@ -3,9 +3,7 @@
   {
    "cell_type": "code",
    "execution_count": 1,
-   "metadata": {
-    "collapsed": false
-   },
+   "metadata": {},
    "outputs": [],
    "source": [
     "import spot\n",
@@ -22,9 +20,7 @@
   {
    "cell_type": "code",
    "execution_count": 2,
-   "metadata": {
-    "collapsed": false
-   },
+   "metadata": {},
    "outputs": [
     {
      "data": {
@@ -149,7 +145,7 @@
        "</svg>\n"
       ],
       "text/plain": [
-       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fb74c39da80> >"
+       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7ff774426a50> >"
       ]
      },
      "execution_count": 2,
@@ -171,9 +167,7 @@
   {
    "cell_type": "code",
    "execution_count": 3,
-   "metadata": {
-    "collapsed": false
-   },
+   "metadata": {},
    "outputs": [
     {
      "data": {
@@ -207,9 +201,7 @@
   {
    "cell_type": "code",
    "execution_count": 4,
-   "metadata": {
-    "collapsed": false
-   },
+   "metadata": {},
    "outputs": [
     {
      "name": "stdout",
@@ -235,9 +227,7 @@
   {
    "cell_type": "code",
    "execution_count": 5,
-   "metadata": {
-    "collapsed": false
-   },
+   "metadata": {},
    "outputs": [
     {
      "data": {
@@ -264,9 +254,7 @@
   {
    "cell_type": "code",
    "execution_count": 6,
-   "metadata": {
-    "collapsed": false
-   },
+   "metadata": {},
    "outputs": [
     {
      "data": {
@@ -301,9 +289,7 @@
   {
    "cell_type": "code",
    "execution_count": 7,
-   "metadata": {
-    "collapsed": false
-   },
+   "metadata": {},
    "outputs": [
     {
      "name": "stdout",
@@ -331,9 +317,7 @@
   {
    "cell_type": "code",
    "execution_count": 8,
-   "metadata": {
-    "collapsed": false
-   },
+   "metadata": {},
    "outputs": [
     {
      "data": {
@@ -361,9 +345,7 @@
   {
    "cell_type": "code",
    "execution_count": 9,
-   "metadata": {
-    "collapsed": false
-   },
+   "metadata": {},
    "outputs": [
     {
      "data": {
@@ -390,9 +372,7 @@
   {
    "cell_type": "code",
    "execution_count": 10,
-   "metadata": {
-    "collapsed": false
-   },
+   "metadata": {},
    "outputs": [
     {
      "name": "stdout",
@@ -413,9 +393,7 @@
   {
    "cell_type": "code",
    "execution_count": 11,
-   "metadata": {
-    "collapsed": false
-   },
+   "metadata": {},
    "outputs": [
     {
      "data": {
@@ -436,9 +414,7 @@
   {
    "cell_type": "code",
    "execution_count": 12,
-   "metadata": {
-    "collapsed": false
-   },
+   "metadata": {},
    "outputs": [
     {
      "data": {
@@ -473,20 +449,7 @@
   {
    "cell_type": "code",
    "execution_count": 13,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [],
-   "source": [
-    "w1 = spot.parse_word('a; !a; cycle{a; !a; a}')"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 14,
-   "metadata": {
-    "collapsed": false
-   },
+   "metadata": {},
    "outputs": [
     {
      "data": {
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       "text/plain": [
-       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fb74c39d990> >"
+       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7ff77439aae0> >"
       ]
      },
-     "execution_count": 14,
+     "execution_count": 13,
      "metadata": {},
      "output_type": "execute_result"
     }
    ],
    "source": [
-    "w1.as_automaton()"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "The rest of this page tests some syntax errors, you (humans) may skip it, but the test suite will not."
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 15,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "ename": "SyntaxError",
-     "evalue": "\n>>> a; b&!a; b\n              ^\nA twa_word must contain a cycle\n (<string>)",
-     "output_type": "error",
-     "traceback": [
-      "\u001b[0;36m  File \u001b[0;32m\"<string>\"\u001b[0;36m, line \u001b[0;32munknown\u001b[0m\n\u001b[0;31mSyntaxError\u001b[0m\u001b[0;31m:\u001b[0m \n>>> a; b&!a; b\n              ^\nA twa_word must contain a cycle\n\n"
-     ]
-    }
-   ],
-   "source": [
-    "print(spot.parse_word('a; b&!a; b'))"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 16,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "ename": "SyntaxError",
-     "evalue": "\n>>> a; b; c}\n           ^\nExpected ';' delimiter: '}' stands for ending a cycle\n (<string>)",
-     "output_type": "error",
-     "traceback": [
-      "\u001b[0;36m  File \u001b[0;32m\"<string>\"\u001b[0;36m, line \u001b[0;32munknown\u001b[0m\n\u001b[0;31mSyntaxError\u001b[0m\u001b[0;31m:\u001b[0m \n>>> a; b; c}\n           ^\nExpected ';' delimiter: '}' stands for ending a cycle\n\n"
-     ]
-    }
-   ],
-   "source": [
-    "print(spot.parse_word('a; b; c}'))"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 17,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "ename": "SyntaxError",
-     "evalue": "\n>>> a; cycle{}\n             ^\nempty input\n\n (<string>)",
-     "output_type": "error",
-     "traceback": [
-      "\u001b[0;36m  File \u001b[0;32m\"<string>\"\u001b[0;36m, line \u001b[0;32munknown\u001b[0m\n\u001b[0;31mSyntaxError\u001b[0m\u001b[0;31m:\u001b[0m \n>>> a; cycle{}\n             ^\nempty input\n\n\n"
-     ]
-    }
-   ],
-   "source": [
-    "print(spot.parse_word('a; cycle{}'))"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 18,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "ename": "SyntaxError",
-     "evalue": "\n>>> a; cycle{!a}; a\n                ^\nInput should be finished after cycle\n (<string>)",
-     "output_type": "error",
-     "traceback": [
-      "\u001b[0;36m  File \u001b[0;32m\"<string>\"\u001b[0;36m, line \u001b[0;32munknown\u001b[0m\n\u001b[0;31mSyntaxError\u001b[0m\u001b[0;31m:\u001b[0m \n>>> a; cycle{!a}; a\n                ^\nInput should be finished after cycle\n\n"
-     ]
-    }
-   ],
-   "source": [
-    "print(spot.parse_word('a; cycle{!a}; a'))"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 19,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [],
-   "source": [
-    "# Creating an empty word is OK...\n",
-    "w = spot.twa_word(spot._bdd_dict)"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 20,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "ename": "RuntimeError",
-     "evalue": "a twa_word may not have an empty cycle",
-     "output_type": "error",
-     "traceback": [
-      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
-      "\u001b[0;31mRuntimeError\u001b[0m                              Traceback (most recent call last)",
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-      "\u001b[0;32m/home/adl/git/spot/python/spot/impl.py\u001b[0m in \u001b[0;36m__str__\u001b[0;34m(self)\u001b[0m\n\u001b[1;32m   4922\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m   4923\u001b[0m     \u001b[0;32mdef\u001b[0m \u001b[0m__str__\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mself\u001b[0m\u001b[0;34m)\u001b[0m \u001b[0;34m->\u001b[0m \u001b[0;34m\"std::string\"\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m-> 4924\u001b[0;31m         \u001b[0;32mreturn\u001b[0m \u001b[0m_impl\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mtwa_word___str__\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mself\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m   4925\u001b[0m \u001b[0mtwa_word_swigregister\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0m_impl\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mtwa_word_swigregister\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m   4926\u001b[0m \u001b[0mtwa_word_swigregister\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mtwa_word\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
-      "\u001b[0;31mRuntimeError\u001b[0m: a twa_word may not have an empty cycle"
-     ]
-    }
-   ],
-   "source": [
-    "# ... as long as this word is not printed.\n",
-    "print(w)"
+    "w.as_automaton()"
    ]
   }
  ],