diff --git a/NEWS b/NEWS
index b9d0f1b46..41bba4198 100644
--- a/NEWS
+++ b/NEWS
@@ -43,6 +43,7 @@ New in spot 1.99.4a (not yet released)
 
   Python:
 
+  * The minimum supported Python version is now 3.3.
   * Add bindings for complete() and dtwa_complement()
   * Formulas now have a custom __format__ function.  See
     https://spot.lrde.epita.fr/tut01.html for examples.
@@ -52,6 +53,9 @@ New in spot 1.99.4a (not yet released)
   * spot.postprocess(aut, *options), or aut.postprocess(*options)
     simplify the use of the spot.postprocessor object.  (Just like we
     have spot.translate() on top of spot.translator().)
+  * spot.automata() and spot.automaton() now have an optional
+    timeout argument to restrict the runtime of commands that
+    produce automata.
 
   Bugs fixed:
 
diff --git a/wrap/python/spot.py b/wrap/python/spot.py
index e723b0dd4..f9878f4b8 100644
--- a/wrap/python/spot.py
+++ b/wrap/python/spot.py
@@ -17,9 +17,16 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+
+import sys
+
+
+if sys.hexversion < 0x03030000:
+    sys.exit("This module requires Python 3.3 or newer")
+
+
 from spot_impl import *
 import subprocess
-import sys
 from functools import lru_cache
 
 
@@ -288,11 +295,21 @@ class formula:
         raise ValueError("unknown type of formula")
 
 
-def automata(*filenames):
+def automata(*sources, timeout=None):
     """Read automata from a list of sources.
 
-    These sources can be either filenames, commands, or some
-    textual represantations of automata.
+    Parameters
+    ----------
+    *sources : list of str
+        These sources can be either commands (end with `|`),
+        textual represantations of automata (contain `\n`),
+        or filenames (else).
+    timeout_error : int, optional
+        Number of seconds to wait for the result of a command.
+        If None (the default), not limit is used.
+
+    Notes
+    -----
 
     The automata can be written in the `HOA format`_, as `never
     claims`_, in `LBTT's format`_, or in `ltl2dstar's format`_.
@@ -316,24 +333,45 @@ def automata(*filenames):
     The result of this function is a generator on all the automata
     objects read from these sources.  The typical usage is::
 
-        for aut in spot.automata(filename):
+        for aut in spot.automata(filename, command, ...):
             # do something with aut
 
+    When the source is a command, and no `timeout` is specified,
+    parsing is done straight out of the pipe connecting the
+    command.  So
+
+        for aut in spot.automata('randaut -H -n 10 2 |'):
+            process(aut)
+
+    will call `process(aut)` on each automaton as soon as it is output by
+    `randaut`, and without waiting for `randaut` to terminate.
+
+    However if `timeout` is passed, then `automata()` will wait for
+    the entire command to terminate before parsing its entire output.
+    If one command takes more than `timeout` seconds,
+    `subprocess.TimeoutExpired` is raised.
+
+    If any command terminates with a non-zero error,
+    `subprocess.CalledProcessError` is raised.
     """
 
-    for filename in filenames:
+    for filename in sources:
         try:
             p = None
+            proc = None
             if filename[-1] == '|':
-                proc = subprocess.Popen(filename[:-1], shell=True,
-                                        stdout=subprocess.PIPE)
-                p = automaton_stream_parser(proc.stdout.fileno(),
-                                            filename, True)
+                if timeout is None:
+                    proc = subprocess.Popen(filename[:-1], shell=True,
+                                            stdout=subprocess.PIPE)
+                    p = automaton_stream_parser(proc.stdout.fileno(),
+                                                filename, True)
+                else:
+                    out = subprocess.check_output(filename[:-1], shell=True,
+                                                  timeout=timeout)
+                    p = automaton_stream_parser(out, filename, True)
             elif '\n' in filename:
-                proc = None
                 p = automaton_stream_parser(filename, "<string>", True)
             else:
-                proc = None
                 p = automaton_stream_parser(filename, True)
             a = True
             while a:
@@ -358,17 +396,16 @@ def automata(*filenames):
                     ret = proc.poll()
                 del proc
                 if ret:
-                    raise RuntimeError("Command {} exited with exit status {}"
-                                       .format(filename[:-1], ret))
+                    raise subprocess.CalledProcessError(ret, filename[:-1])
     return
 
 
-def automaton(filename):
+def automaton(filename, **kwargs):
     """Read a single automaton from a file.
 
     See `spot.automata` for a list of supported formats."""
     try:
-        return next(automata(filename))
+        return next(automata(filename, **kwargs))
     except StopIteration:
         raise RuntimeError("Failed to read automaton from {}".format(filename))
 
diff --git a/wrap/python/tests/automata-io.ipynb b/wrap/python/tests/automata-io.ipynb
index 99ede1e25..9ac2fd57d 100644
--- a/wrap/python/tests/automata-io.ipynb
+++ b/wrap/python/tests/automata-io.ipynb
@@ -17,7 +17,8 @@
    "pygments_lexer": "ipython3",
    "version": "3.4.3+"
   },
-  "name": ""
+  "name": "",
+  "signature": "sha256:79ee85572b2a0147d88b2d3d355977e3f34dadb82bd7e8589bdbb2cf2a539b0b"
  },
  "nbformat": 3,
  "nbformat_minor": 0,
@@ -171,7 +172,7 @@
         "</svg>\n"
        ],
        "text": [
-        "<spot_impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f4d702fb090> >"
+        "<spot_impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f4414147600> >"
        ]
       }
      ],
@@ -282,7 +283,7 @@
         "</svg>\n"
        ],
        "text": [
-        "<spot_impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f4d702fb060> >"
+        "<spot_impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f4414157570> >"
        ]
       },
       {
@@ -339,7 +340,7 @@
         "</svg>\n"
        ],
        "text": [
-        "<spot_impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f4d702fb0f0> >"
+        "<spot_impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f4414157660> >"
        ]
       }
      ],
@@ -458,7 +459,7 @@
         "</svg>\n"
        ],
        "text": [
-        "<spot_impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f4d702fb180> >"
+        "<spot_impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f441765be40> >"
        ]
       }
      ],
@@ -553,7 +554,7 @@
         "</svg>\n"
        ],
        "text": [
-        "<spot_impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f4d702e67b0> >"
+        "<spot_impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f4414157690> >"
        ]
       },
       {
@@ -601,7 +602,7 @@
         "</svg>\n"
        ],
        "text": [
-        "<spot_impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f4d702e6720> >"
+        "<spot_impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f441765be40> >"
        ]
       }
      ],
@@ -716,7 +717,7 @@
         "</svg>\n"
        ],
        "text": [
-        "<spot_impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f4d71fbfc90> >"
+        "<spot_impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f44141578d0> >"
        ]
       },
       {
@@ -724,7 +725,7 @@
        "evalue": "\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 (<string>)",
        "output_type": "pyerr",
        "traceback": [
-        "\u001b[1;36m  File \u001b[1;32m\"<string>\"\u001b[1;36m, line \u001b[1;32munknown\u001b[0m\n\u001b[1;31mSyntaxError\u001b[0m\u001b[1;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"
+        "\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"
        ]
       }
      ],
@@ -734,38 +735,65 @@
      "cell_type": "code",
      "collapsed": false,
      "input": [
-      "rm example.aut"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [],
-     "prompt_number": 11
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "spot.automaton('example.aut')"
+      "spot.automaton('example.aut', timeout=100)"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [
       {
-       "ename": "RuntimeError",
-       "evalue": "Cannot open file example.aut",
-       "output_type": "pyerr",
-       "traceback": [
-        "\u001b[1;31m---------------------------------------------------------------------------\u001b[0m",
-        "\u001b[1;31mRuntimeError\u001b[0m                              Traceback (most recent call last)",
-        "\u001b[1;32m<ipython-input-12-91499c480122>\u001b[0m in \u001b[0;36m<module>\u001b[1;34m()\u001b[0m\n\u001b[1;32m----> 1\u001b[1;33m \u001b[0mspot\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mautomaton\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;34m'example.aut'\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m",
-        "\u001b[1;32m/home-ssd/adl/git/spot/wrap/python/spot.py\u001b[0m in \u001b[0;36mautomaton\u001b[1;34m(filename)\u001b[0m\n\u001b[0;32m    216\u001b[0m     See `spot.automata()` for a list of supported formats.\"\"\"\n\u001b[0;32m    217\u001b[0m     \u001b[1;32mtry\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m--> 218\u001b[1;33m         \u001b[1;32mreturn\u001b[0m \u001b[0mnext\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mautomata\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mfilename\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m\u001b[0;32m    219\u001b[0m     \u001b[1;32mexcept\u001b[0m \u001b[0mStopIteration\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    220\u001b[0m         \u001b[1;32mraise\u001b[0m \u001b[0mRuntimeError\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;34m\"Failed to read automaton from {}\"\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mformat\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mfilename\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n",
-        "\u001b[1;32m/home-ssd/adl/git/spot/wrap/python/spot.py\u001b[0m in \u001b[0;36mautomata\u001b[1;34m(*filenames)\u001b[0m\n\u001b[0;32m    183\u001b[0m             \u001b[1;32melse\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    184\u001b[0m                 \u001b[0mproc\u001b[0m \u001b[1;33m=\u001b[0m \u001b[1;32mNone\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m--> 185\u001b[1;33m                 \u001b[0mp\u001b[0m \u001b[1;33m=\u001b[0m \u001b[0mautomaton_stream_parser\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mfilename\u001b[0m\u001b[1;33m,\u001b[0m \u001b[1;32mTrue\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m\u001b[0;32m    186\u001b[0m             \u001b[0ma\u001b[0m \u001b[1;33m=\u001b[0m \u001b[1;32mTrue\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    187\u001b[0m             \u001b[1;32mwhile\u001b[0m \u001b[0ma\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n",
-        "\u001b[1;32m/home-ssd/adl/git/spot/wrap/python/spot_impl.py\u001b[0m in \u001b[0;36m__init__\u001b[1;34m(self, *args)\u001b[0m\n\u001b[0;32m   2452\u001b[0m     \u001b[0m__repr__\u001b[0m \u001b[1;33m=\u001b[0m \u001b[0m_swig_repr\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m   2453\u001b[0m     \u001b[1;32mdef\u001b[0m \u001b[0m__init__\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mself\u001b[0m\u001b[1;33m,\u001b[0m \u001b[1;33m*\u001b[0m\u001b[0margs\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m-> 2454\u001b[1;33m         \u001b[0mthis\u001b[0m \u001b[1;33m=\u001b[0m \u001b[0m_spot_impl\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mnew_automaton_stream_parser\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;33m*\u001b[0m\u001b[0margs\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m\u001b[0;32m   2455\u001b[0m         \u001b[1;32mtry\u001b[0m\u001b[1;33m:\u001b[0m \u001b[0mself\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mthis\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mappend\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mthis\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m   2456\u001b[0m         \u001b[1;32mexcept\u001b[0m\u001b[1;33m:\u001b[0m \u001b[0mself\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mthis\u001b[0m \u001b[1;33m=\u001b[0m \u001b[0mthis\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n",
-        "\u001b[1;31mRuntimeError\u001b[0m: Cannot open file example.aut"
+       "metadata": {},
+       "output_type": "pyout",
+       "prompt_number": 11,
+       "svg": [
+        "<?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",
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+        "</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",
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+        "<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": [
+        "<spot_impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f44141578a0> >"
        ]
       }
      ],
-     "prompt_number": 12
+     "prompt_number": 11
     },
     {
      "cell_type": "code",
@@ -777,16 +805,40 @@
      "metadata": {},
      "outputs": [
       {
-       "ename": "RuntimeError",
-       "evalue": "Command non-existing-cmd  exited with exit status 127",
+       "ename": "CalledProcessError",
+       "evalue": "Command 'non-existing-cmd ' returned non-zero exit status 127",
        "output_type": "pyerr",
        "traceback": [
-        "\u001b[1;31m---------------------------------------------------------------------------\u001b[0m",
-        "\u001b[1;31mRuntimeError\u001b[0m                              Traceback (most recent call last)",
-        "\u001b[1;32m<ipython-input-13-2b2d1b66dcd6>\u001b[0m in \u001b[0;36m<module>\u001b[1;34m()\u001b[0m\n\u001b[1;32m----> 1\u001b[1;33m \u001b[0mspot\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mautomaton\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;34m'non-existing-cmd |'\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m",
-        "\u001b[1;32m/home-ssd/adl/git/spot/wrap/python/spot.py\u001b[0m in \u001b[0;36mautomaton\u001b[1;34m(filename)\u001b[0m\n\u001b[0;32m    216\u001b[0m     See `spot.automata()` for a list of supported formats.\"\"\"\n\u001b[0;32m    217\u001b[0m     \u001b[1;32mtry\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m--> 218\u001b[1;33m         \u001b[1;32mreturn\u001b[0m \u001b[0mnext\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mautomata\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mfilename\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m\u001b[0;32m    219\u001b[0m     \u001b[1;32mexcept\u001b[0m \u001b[0mStopIteration\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    220\u001b[0m         \u001b[1;32mraise\u001b[0m \u001b[0mRuntimeError\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;34m\"Failed to read automaton from {}\"\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mformat\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mfilename\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n",
-        "\u001b[1;32m/home-ssd/adl/git/spot/wrap/python/spot.py\u001b[0m in \u001b[0;36mautomata\u001b[1;34m(*filenames)\u001b[0m\n\u001b[0;32m    208\u001b[0m                 \u001b[1;32mif\u001b[0m \u001b[0mret\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    209\u001b[0m                     raise RuntimeError(\"Command {} exited with exit status {}\"\n\u001b[1;32m--> 210\u001b[1;33m                                        .format(filename[:-1], ret))\n\u001b[0m\u001b[0;32m    211\u001b[0m     \u001b[1;32mreturn\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    212\u001b[0m \u001b[1;33m\u001b[0m\u001b[0m\n",
-        "\u001b[1;31mRuntimeError\u001b[0m: Command non-existing-cmd  exited with exit status 127"
+        "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m\n\u001b[0;31mCalledProcessError\u001b[0m                        Traceback (most recent call last)",
+        "\u001b[0;32m<ipython-input-12-2b2d1b66dcd6>\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/wrap/python/spot.py\u001b[0m in \u001b[0;36mautomaton\u001b[0;34m(filename, **kwargs)\u001b[0m\n\u001b[1;32m    404\u001b[0m     See `spot.automata` for a list of supported formats.\"\"\"\n\u001b[1;32m    405\u001b[0m     \u001b[0;32mtry\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 406\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    407\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    408\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/wrap/python/spot.py\u001b[0m in \u001b[0;36mautomata\u001b[0;34m(timeout, *sources)\u001b[0m\n\u001b[1;32m    395\u001b[0m                 \u001b[0;32mdel\u001b[0m \u001b[0mproc\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    396\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--> 397\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    398\u001b[0m     \u001b[0;32mreturn\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    399\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"
+       ]
+      }
+     ],
+     "prompt_number": 12
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "spot.automaton('sleep 3; cat example.aut |', timeout=1)"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "ename": "TimeoutExpired",
+       "evalue": "Command 'sleep 3; cat example.aut ' timed out after 1 seconds",
+       "output_type": "pyerr",
+       "traceback": [
+        "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m\n\u001b[0;31mTimeoutExpired\u001b[0m                            Traceback (most recent call last)",
+        "\u001b[0;32m<ipython-input-13-d9c814f4e517>\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/wrap/python/spot.py\u001b[0m in \u001b[0;36mautomaton\u001b[0;34m(filename, **kwargs)\u001b[0m\n\u001b[1;32m    404\u001b[0m     See `spot.automata` for a list of supported formats.\"\"\"\n\u001b[1;32m    405\u001b[0m     \u001b[0;32mtry\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 406\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    407\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    408\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/wrap/python/spot.py\u001b[0m in \u001b[0;36mautomata\u001b[0;34m(timeout, *sources)\u001b[0m\n\u001b[1;32m    366\u001b[0m                 \u001b[0;32melse\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    367\u001b[0m                     out = subprocess.check_output(filename[:-1], shell=True,\n\u001b[0;32m--> 368\u001b[0;31m                                                   timeout=timeout)\n\u001b[0m\u001b[1;32m    369\u001b[0m                     \u001b[0mp\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0mautomaton_stream_parser\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mout\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mfilename\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0;32mTrue\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    370\u001b[0m             \u001b[0;32melif\u001b[0m \u001b[0;34m'\\n'\u001b[0m \u001b[0;32min\u001b[0m \u001b[0mfilename\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
+        "\u001b[0;32m/usr/lib/python3.4/subprocess.py\u001b[0m in \u001b[0;36mcheck_output\u001b[0;34m(timeout, *popenargs, **kwargs)\u001b[0m\n\u001b[1;32m    611\u001b[0m             \u001b[0mprocess\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mkill\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    612\u001b[0m             \u001b[0moutput\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0munused_err\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0mprocess\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mcommunicate\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 613\u001b[0;31m             \u001b[0;32mraise\u001b[0m \u001b[0mTimeoutExpired\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mprocess\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0margs\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mtimeout\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0moutput\u001b[0m\u001b[0;34m=\u001b[0m\u001b[0moutput\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m    614\u001b[0m         \u001b[0;32mexcept\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    615\u001b[0m             \u001b[0mprocess\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mkill\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m)\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"
        ]
       }
      ],
@@ -795,14 +847,16 @@
     {
      "cell_type": "code",
      "collapsed": false,
-     "input": [],
+     "input": [
+      "rm example.aut"
+     ],
      "language": "python",
      "metadata": {},
      "outputs": [],
-     "prompt_number": null
+     "prompt_number": 14
     }
    ],
    "metadata": {}
   }
  ]
-}
+}
\ No newline at end of file
diff --git a/wrap/python/tests/piperead.ipynb b/wrap/python/tests/piperead.ipynb
index 959790d2d..c82d8aad5 100644
--- a/wrap/python/tests/piperead.ipynb
+++ b/wrap/python/tests/piperead.ipynb
@@ -17,7 +17,8 @@
    "pygments_lexer": "ipython3",
    "version": "3.4.3+"
   },
-  "name": ""
+  "name": "",
+  "signature": "sha256:471d70bbd30f4ffde7ebceb35a8f4a1ca66baba3ad959b99d4bb72ef81e4d5cf"
  },
  "nbformat": 3,
  "nbformat_minor": 0,
@@ -110,7 +111,7 @@
         "</svg>\n"
        ],
        "text": [
-        "<spot_impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f3fa02ed390> >"
+        "<spot_impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f1084090540> >"
        ]
       },
       {
@@ -161,7 +162,7 @@
         "</svg>\n"
        ],
        "text": [
-        "<spot_impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f3fa02ed420> >"
+        "<spot_impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f1084090600> >"
        ]
       },
       {
@@ -207,7 +208,7 @@
         "</svg>\n"
        ],
        "text": [
-        "<spot_impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f3fa02ed3f0> >"
+        "<spot_impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f1084090540> >"
        ]
       },
       {
@@ -264,7 +265,7 @@
         "</svg>\n"
        ],
        "text": [
-        "<spot_impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f3fa02ed390> >"
+        "<spot_impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f1084090600> >"
        ]
       }
      ],
@@ -341,7 +342,7 @@
         "</svg>\n"
        ],
        "text": [
-        "<spot_impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f3fa02ed480> >"
+        "<spot_impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f10840a0570> >"
        ]
       }
      ],
@@ -366,16 +367,15 @@
      "metadata": {},
      "outputs": [
       {
-       "ename": "RuntimeError",
-       "evalue": "Command non-existing-command exited with exit status 127",
+       "ename": "CalledProcessError",
+       "evalue": "Command 'non-existing-command' returned non-zero exit status 127",
        "output_type": "pyerr",
        "traceback": [
-        "\u001b[1;31m---------------------------------------------------------------------------\u001b[0m",
-        "\u001b[1;31mRuntimeError\u001b[0m                              Traceback (most recent call last)",
-        "\u001b[1;32m<ipython-input-4-765c7cc6937f>\u001b[0m in \u001b[0;36m<module>\u001b[1;34m()\u001b[0m\n\u001b[1;32m----> 1\u001b[1;33m \u001b[0mspot\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mautomaton\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;34m'non-existing-command|'\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m",
-        "\u001b[1;32m/home-ssd/adl/git/spot/wrap/python/spot.py\u001b[0m in \u001b[0;36mautomaton\u001b[1;34m(filename)\u001b[0m\n\u001b[0;32m    369\u001b[0m     See `spot.automata` for a list of supported formats.\"\"\"\n\u001b[0;32m    370\u001b[0m     \u001b[1;32mtry\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m--> 371\u001b[1;33m         \u001b[1;32mreturn\u001b[0m \u001b[0mnext\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mautomata\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mfilename\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m\u001b[0;32m    372\u001b[0m     \u001b[1;32mexcept\u001b[0m \u001b[0mStopIteration\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    373\u001b[0m         \u001b[1;32mraise\u001b[0m \u001b[0mRuntimeError\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;34m\"Failed to read automaton from {}\"\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mformat\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mfilename\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n",
-        "\u001b[1;32m/home-ssd/adl/git/spot/wrap/python/spot.py\u001b[0m in \u001b[0;36mautomata\u001b[1;34m(*filenames)\u001b[0m\n\u001b[0;32m    360\u001b[0m                 \u001b[1;32mif\u001b[0m \u001b[0mret\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    361\u001b[0m                     raise RuntimeError(\"Command {} exited with exit status {}\"\n\u001b[1;32m--> 362\u001b[1;33m                                        .format(filename[:-1], ret))\n\u001b[0m\u001b[0;32m    363\u001b[0m     \u001b[1;32mreturn\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    364\u001b[0m \u001b[1;33m\u001b[0m\u001b[0m\n",
-        "\u001b[1;31mRuntimeError\u001b[0m: Command non-existing-command exited with exit status 127"
+        "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m\n\u001b[0;31mCalledProcessError\u001b[0m                        Traceback (most recent call last)",
+        "\u001b[0;32m<ipython-input-4-765c7cc6937f>\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/wrap/python/spot.py\u001b[0m in \u001b[0;36mautomaton\u001b[0;34m(filename, **kwargs)\u001b[0m\n\u001b[1;32m    404\u001b[0m     See `spot.automata` for a list of supported formats.\"\"\"\n\u001b[1;32m    405\u001b[0m     \u001b[0;32mtry\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 406\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    407\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    408\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/wrap/python/spot.py\u001b[0m in \u001b[0;36mautomata\u001b[0;34m(timeout, *sources)\u001b[0m\n\u001b[1;32m    395\u001b[0m                 \u001b[0;32mdel\u001b[0m \u001b[0mproc\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    396\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--> 397\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    398\u001b[0m     \u001b[0;32mreturn\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    399\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"
        ]
       }
      ],
@@ -445,19 +445,18 @@
         "</svg>\n"
        ],
        "text": [
-        "<spot_impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f3fa02edea0> >"
+        "<spot_impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f10840a00c0> >"
        ]
       },
       {
-       "ename": "RuntimeError",
-       "evalue": "Command ltl2tgba -f \"syntax U U error\" exited with exit status 2",
+       "ename": "CalledProcessError",
+       "evalue": "Command 'ltl2tgba -f \"syntax U U error\"' returned non-zero exit status 2",
        "output_type": "pyerr",
        "traceback": [
-        "\u001b[1;31m---------------------------------------------------------------------------\u001b[0m",
-        "\u001b[1;31mRuntimeError\u001b[0m                              Traceback (most recent call last)",
-        "\u001b[1;32m<ipython-input-5-21a24ff75c32>\u001b[0m in \u001b[0;36m<module>\u001b[1;34m()\u001b[0m\n\u001b[1;32m----> 1\u001b[1;33m \u001b[1;32mfor\u001b[0m \u001b[0ma\u001b[0m \u001b[1;32min\u001b[0m \u001b[0mspot\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mautomata\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;34m\"ltl2tgba -H 'a U b'|\"\u001b[0m\u001b[1;33m,\u001b[0m \u001b[1;34m'ltl2tgba -f \"syntax U U error\"|'\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m\u001b[0;32m      2\u001b[0m     \u001b[0mdisplay\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0ma\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n",
-        "\u001b[1;32m/home-ssd/adl/git/spot/wrap/python/spot.py\u001b[0m in \u001b[0;36mautomata\u001b[1;34m(*filenames)\u001b[0m\n\u001b[0;32m    360\u001b[0m                 \u001b[1;32mif\u001b[0m \u001b[0mret\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    361\u001b[0m                     raise RuntimeError(\"Command {} exited with exit status {}\"\n\u001b[1;32m--> 362\u001b[1;33m                                        .format(filename[:-1], ret))\n\u001b[0m\u001b[0;32m    363\u001b[0m     \u001b[1;32mreturn\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    364\u001b[0m \u001b[1;33m\u001b[0m\u001b[0m\n",
-        "\u001b[1;31mRuntimeError\u001b[0m: Command ltl2tgba -f \"syntax U U error\" exited with exit status 2"
+        "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m\n\u001b[0;31mCalledProcessError\u001b[0m                        Traceback (most recent call last)",
+        "\u001b[0;32m<ipython-input-5-21a24ff75c32>\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 -H 'a U b'|\"\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0;34m'ltl2tgba -f \"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/wrap/python/spot.py\u001b[0m in \u001b[0;36mautomata\u001b[0;34m(timeout, *sources)\u001b[0m\n\u001b[1;32m    395\u001b[0m                 \u001b[0;32mdel\u001b[0m \u001b[0mproc\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    396\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--> 397\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    398\u001b[0m     \u001b[0;32mreturn\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    399\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n",
+        "\u001b[0;31mCalledProcessError\u001b[0m: Command 'ltl2tgba -f \"syntax U U error\"' returned non-zero exit status 2"
        ]
       }
      ],
@@ -474,35 +473,24 @@
      "cell_type": "code",
      "collapsed": false,
      "input": [
-      "spot.automaton('false|')"
+      "spot.automaton('true|')"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [
       {
        "ename": "RuntimeError",
-       "evalue": "Command false exited with exit status 1",
+       "evalue": "Failed to read automaton from true|",
        "output_type": "pyerr",
        "traceback": [
-        "\u001b[1;31m---------------------------------------------------------------------------\u001b[0m",
-        "\u001b[1;31mRuntimeError\u001b[0m                              Traceback (most recent call last)",
-        "\u001b[1;32m<ipython-input-6-029e1e5901f7>\u001b[0m in \u001b[0;36m<module>\u001b[1;34m()\u001b[0m\n\u001b[1;32m----> 1\u001b[1;33m \u001b[0mspot\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mautomaton\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;34m'false|'\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m",
-        "\u001b[1;32m/home-ssd/adl/git/spot/wrap/python/spot.py\u001b[0m in \u001b[0;36mautomaton\u001b[1;34m(filename)\u001b[0m\n\u001b[0;32m    369\u001b[0m     See `spot.automata` for a list of supported formats.\"\"\"\n\u001b[0;32m    370\u001b[0m     \u001b[1;32mtry\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[1;32m--> 371\u001b[1;33m         \u001b[1;32mreturn\u001b[0m \u001b[0mnext\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mautomata\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mfilename\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0m\u001b[0;32m    372\u001b[0m     \u001b[1;32mexcept\u001b[0m \u001b[0mStopIteration\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    373\u001b[0m         \u001b[1;32mraise\u001b[0m \u001b[0mRuntimeError\u001b[0m\u001b[1;33m(\u001b[0m\u001b[1;34m\"Failed to read automaton from {}\"\u001b[0m\u001b[1;33m.\u001b[0m\u001b[0mformat\u001b[0m\u001b[1;33m(\u001b[0m\u001b[0mfilename\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m)\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n",
-        "\u001b[1;32m/home-ssd/adl/git/spot/wrap/python/spot.py\u001b[0m in \u001b[0;36mautomata\u001b[1;34m(*filenames)\u001b[0m\n\u001b[0;32m    360\u001b[0m                 \u001b[1;32mif\u001b[0m \u001b[0mret\u001b[0m\u001b[1;33m:\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    361\u001b[0m                     raise RuntimeError(\"Command {} exited with exit status {}\"\n\u001b[1;32m--> 362\u001b[1;33m                                        .format(filename[:-1], ret))\n\u001b[0m\u001b[0;32m    363\u001b[0m     \u001b[1;32mreturn\u001b[0m\u001b[1;33m\u001b[0m\u001b[0m\n\u001b[0;32m    364\u001b[0m \u001b[1;33m\u001b[0m\u001b[0m\n",
-        "\u001b[1;31mRuntimeError\u001b[0m: Command false exited with exit status 1"
+        "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m\n\u001b[0;31mRuntimeError\u001b[0m                              Traceback (most recent call last)",
+        "\u001b[0;32m<ipython-input-6-f4e056a50029>\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/wrap/python/spot.py\u001b[0m in \u001b[0;36mautomaton\u001b[0;34m(filename, **kwargs)\u001b[0m\n\u001b[1;32m    406\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    407\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--> 408\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    409\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    410\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n",
+        "\u001b[0;31mRuntimeError\u001b[0m: Failed to read automaton from true|"
        ]
       }
      ],
      "prompt_number": 6
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": [],
-     "prompt_number": null
     }
    ],
    "metadata": {}