python: move auxiliary functions in a separate module

* python/spot/aux.py: New file, with function extracted from...
* python/spot/__init__.py: ... here.
* python/.gitignore, python/Makefile.am: Adjust.

python/.gitignore

@@ -3,7 +3,6 @@
 Makefile
 Makefile.in
 *.la
-spot_impl.py*
 buddy.py*
 *.lo
 *.loT
@@ -11,4 +10,5 @@ buddy.py*
 *.pyc
 */spotimg
 ajax/*.py
-spot/*.py
+spot/impl.py
+spot/ltsmin.py

python/Makefile.am

@@ -37,6 +37,7 @@ SWIGFLAGS = -c++ -python -py3 -O -nofastproxy
 EXTRA_DIST = buddy.i spot/impl.i spot/ltsmin.i
 nobase_python_PYTHON = \
   spot/__init__.py \
+  spot/aux.py \
   spot/impl.py \
   spot/ltsmin.py \
   buddy.py

python/spot/__init__.py

@@ -26,28 +26,19 @@ if sys.hexversion < 0x03030000:
 
 
 from spot.impl import *
+from spot.aux import \
+     extend as _extend, \
+     str_to_svg as _str_to_svg, \
+     ostream_to_svg as _ostream_to_svg
 import subprocess
 import os
 import signal
-from functools import lru_cache
 
 
-def _extend(*classes):
-    """
-    Decorator that extends all the given classes with the contents
-    of the class currently being defined.
-    """
-    def wrap(this):
-        for cls in classes:
-            for (name, val) in this.__dict__.items():
-                if name not in ('__dict__', '__weakref__') \
-                   and not (name == '__doc__' and val is None):
-                    setattr(cls, name, val)
-        return classes[0]
-    return wrap
-
+# The parrameters used by default when show() is called on an automaton.
 _show_default = None
 
+
 def setup(**kwargs):
     """Configure Spot for fancy display.
 
@@ -108,23 +99,6 @@ if 'op_ff' not in globals():
 _bdd_dict = make_bdd_dict()
 
 
-# Add a small LRU cache so that when we display automata into a
-# interactive widget, we avoid some repeated calls to dot for
-# identical inputs.
-@lru_cache(maxsize=64)
-def _str_to_svg(str):
-    dotty = subprocess.Popen(['dot', '-Tsvg'],
-                             stdin=subprocess.PIPE,
-                             stdout=subprocess.PIPE)
-    dotty.stdin.write(str)
-    res = dotty.communicate()
-    return res[0].decode('utf-8')
-
-
-def _ostream_to_svg(ostr):
-    return _str_to_svg(ostr.str().encode('utf-8'))
-
-
 @_extend(twa, ta)
 class twa:
     def _repr_svg_(self, opt=None):

python/spot/aux.py

@@ -0,0 +1,62 @@
+# -*- coding: utf-8 -*-
+# Copyright (C) 2016 Laboratoire de Recherche et Développement de l'Epita
+# (LRDE).
+#
+# This file is part of Spot, a model checking library.
+#
+# Spot is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# Spot is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+# or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+# License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""
+Auxiliary functions for Spot's Python bindings
+"""
+
+from functools import lru_cache
+import subprocess
+
+
+def extend(*classes):
+    """
+    Decorator that extends all the given classes with the contents
+    of the class currently being defined.
+    """
+    def wrap(this):
+        for cls in classes:
+            for (name, val) in this.__dict__.items():
+                if name not in ('__dict__', '__weakref__') \
+                   and not (name == '__doc__' and val is None):
+                    setattr(cls, name, val)
+        return classes[0]
+    return wrap
+
+
+# Add a small LRU cache so that when we display automata into a
+# interactive widget, we avoid some repeated calls to dot for
+# identical inputs.
+@lru_cache(maxsize=64)
+def str_to_svg(str):
+    """
+    Send some text to dot for conversion to SVG.
+    """
+    dot = subprocess.Popen(['dot', '-Tsvg'],
+                           stdin=subprocess.PIPE,
+                           stdout=subprocess.PIPE)
+    res = dot.communicate(str)
+    return res[0].decode('utf-8')
+
+
+def ostream_to_svg(ostr):
+    """
+    Encode an ostringstream as utf-8 and send it to dot for cocnversion to SVG.
+    """
+    return str_to_svg(ostr.str().encode('utf-8'))