multiple adjustments for Debian stable

* tests/python/ipnbdoctest.py: Adjust to Python <3.6.
* tests/python/_autparserr.ipynb: Adjust to older IPython version.
* tests/python/stutter-inv.ipynb: Avoid pandas because its output
varies from version to version.

tests/python/_autparserr.ipynb

@@ -6,6 +6,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
+    "from IPython.display import display\n",
     "import spot\n",
     "spot.setup()"
    ]
@@ -27,7 +28,7 @@
      "name": "stdout",
      "output_type": "stream",
      "text": [
-      "Overwriting _example.aut\n"
+      "Writing _example.aut\n"
      ]
     }
    ],
@@ -111,7 +112,7 @@
        "</svg>\n"
       ],
       "text/plain": [
-       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fbec845de70> >"
+       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f72fc2978d0> >"
       ]
      },
      "metadata": {},
@@ -183,7 +184,7 @@
        "</svg>\n"
       ],
       "text/plain": [
-       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fbec846c5a0> >"
+       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f72fc2ce090> >"
       ]
      },
      "execution_count": 4,
@@ -309,7 +310,7 @@
        "</svg>\n"
       ],
       "text/plain": [
-       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7fbec846c570> >"
+       "<spot.impl.twa_graph; proxy of <Swig Object of type 'std::shared_ptr< spot::twa_graph > *' at 0x7f72fc2ce5a0> >"
       ]
      },
      "metadata": {},

tests/python/ipnbdoctest.py

@@ -115,12 +115,9 @@ def canonicalize(s, type, ignores):
     s = re.sub(r' fill="black"', '', s)
     s = re.sub(r' stroke="transparent"', ' stroke="none"', s)
     s = re.sub(r'><title>', '>\n<title>', s)
-    # Different Pandas versions produce different CSS styles.
-    s = re.sub(r'<style[ a-z]*>.*</style>',
-               '<style>...</style>', s, flags=re.DOTALL)
-
-    # CalledProcessError message has a final dot in Python 3.6
-    s = re.sub(r"(' returned non-zero exit status \d+)\.", r'\1', s)
+    # Different Pandas versions produce different CSS styles (when there is a
+    # style).
+    s = re.sub(r'<style[ a-z]*>.*</style>\n', '', s, flags=re.DOTALL)
 
     for n, p in enumerate(ignores):
         s = re.sub(p, 'IGN{}'.format(n), s)
@@ -145,6 +142,12 @@ def canonical_dict(dict, ignores):
         # sys.exit(77) is used to Skip the test.
         sys.exit(77)
 
+    if 'ename' in dict and dict['ename'] == 'CalledProcessError':
+        # CalledProcessError message has a final dot in Python 3.6
+        dict['evalue'] = \
+          re.sub(r"(' returned non-zero exit status \d+)\.", r'\1',
+                 dict['evalue'])
+
     if 'transient' in dict:
         del dict['transient']
     if 'execution_count' in dict: