org-babel-tangle: Provide a Python script to extract tangles from org-mode.

It removes the dependency we had on emacs org-babel mode to launch the tests.
Now examples in .org files are automatically extracted using this script

doc/Makefile

@@ -4,4 +4,4 @@
 	emacs -batch $^ -f "org-html-export-to-html"
 
 analysis-example%: format-analysis.org
-	emacs -batch $^ -f "org-babel-tangle"
+	python ../tools/org-babel-tangle.py --all $^

tools/org-babel-tangle.py

+import argparse
+import re
+import os
+import sys
+
+parser = argparse.ArgumentParser(description = 'Simulate org-babel-tangle emacs function')
+parser.add_argument('--all', '-a', action='store_true', help='Extract all the tangle org babel code')
+parser.add_argument('--extract', '-e', default=[], action='append', help='Extract the org-babel code whose :tangle value is provided by this option')
+parser.add_argument('--directory', '-d', default='.', help = 'Directory where the output files are stored (default is %(default)s). The directory must exist.')
+parser.add_argument('--test', '-t', action='store_true', help='Launch self-tests.')
+parser.add_argument('file', nargs='?', type=argparse.FileType('r'), default=sys.stdin, help='.org file')
+
+args = parser.parse_args()
+
+def export_tangle(filename, content):
+    file = open(filename, "w")
+    file.write(content)
+    file.close()
+                
+def extract_tangle(content, names=None):
+    r'''
+    Extract a tangle from an .org file
+
+    >>> extract_tangle('\n#+BEGIN_SRC sh :tangle ex1 :var ex=2\necho $ex\n#+END_SRC')
+    [{'content': 'echo $ex', 'filename': 'ex1'}]
+    >>> extract_tangle('\n#+BEGIN_SRC sh :tangle ex2 :var ex=2\necho $ex\n#+END_SRC', ['ex2'])
+    [{'content': 'echo $ex', 'filename': 'ex2'}]
+    '''
+    if names == None:
+        names = ['[^ \t\n]+']
+    
+    tangles = []
+    for name in names:
+        regex = '\n\#\+BEGIN_SRC[^\n]*:tangle ('+name+')[^\n]*\n(.*?)\n#\+END_SRC'
+        compiled_regex = re.compile(regex, re.DOTALL)
+        results = compiled_regex.findall(content)
+
+        for result in results:
+            current_tangle = {'filename': result[0],
+                              'content': result[1]}
+            tangles.append(current_tangle)
+    return tangles
+
+def extract_tangle_and_output(content, dir, names=None):
+    tangles = extract_tangle(content, names)
+    for result in tangles:
+        export_tangle(dir + os.sep + result['filename'],
+                      result['content'])
+
+if args.test:
+    import doctest
+    doctest.testmod(verbose = True)
+    sys.exit(0)
+
+content = args.file.read()
+
+if args.all:
+    extract_tangle_and_output(content, args.directory)
+else:
+    extract_tangle_and_output(content, args.directory, args.extract)

tools/tests/Makefile

@@ -14,6 +14,7 @@ doctests:
 	@echo "*** Launching python tests..."
 	python -m doctest -v ../fuse.py
 	python -m doctest -v ../utils.py
+	python ../org-babel-tangle.py --test
 	@echo "*** All python tests passed"
 
 force: