add option to make a lite version without porn site extractors

Makefile

@@ -92,6 +92,9 @@ youtube-dl.fish: youtube_dl/*.py youtube_dl/*/*.py devscripts/fish-completion.in
 
 fish-completion: youtube-dl.fish
 
+remove-porn:
+	python devscripts/remove-porn.py
+
 youtube-dl.tar.gz: youtube-dl README.md README.txt youtube-dl.1 youtube-dl.bash-completion youtube-dl.zsh youtube-dl.fish
 	@tar -czf youtube-dl.tar.gz --transform "s|^|youtube-dl/|" --owner 0 --group 0 \
 		--exclude '*.DS_Store' \

devscripts/remove-porn.py

@@ -0,0 +1,39 @@
+from youtube_dl.extractor import *
+import re
+import os
+
+def list_non_suitable_extractors(age_limit):
+    """
+    Return a list of extractors that are suitable for the given age,
+    sorted by extractor ID.
+    """
+
+    return sorted(
+        filter(lambda ie: not ie.is_suitable(age_limit), gen_extractors()),
+        key=lambda ie: ie.IE_NAME.lower())
+
+non_suitable_extractors = list_non_suitable_extractors(0)
+
+extractors_dir = 'youtube_dl/extractor/'
+
+with open(extractors_dir + '__init__.py') as f:
+    content = f.read()
+    for extractor in non_suitable_extractors:
+        content = re.sub(r'from \.' + extractor.__module__.split('.')[-1] + r' import (?:[A-Za-z0-9,\s]+|\([^\)]+\))\n', '', content)
+
+with open(extractors_dir + '__init__.py', 'w') as f:
+    f.write(content)
+
+with open(extractors_dir + 'generic.py') as f:
+    content = f.read()
+    for extractor in non_suitable_extractors:
+        content = re.sub(r'from \.' + extractor.__module__.split('.')[-1] + r' import (?:[A-Za-z0-9,\s]+|\([^\)]+\))\n', '', content)
+        content = re.sub(r'#[^#]+' + extractor.__module__.split('.')[-1] + r'[^#]+', '', content)
+
+with open(extractors_dir + 'generic.py', 'w') as f:
+    f.write(content)
+
+for extractor in non_suitable_extractors:
+    extractor_filename = extractors_dir + extractor.__module__.split('.')[-1] + '.py'
+    if os.path.isfile(extractor_filename):
+        os.remove(extractor_filename)