http://bugs.python.org/review/18562/diff/8741/Doc/howto/regex.rst File Doc/howto/regex.rst (right): http://bugs.python.org/review/18562/diff/8741/Doc/howto/regex.rst#newcode514 Doc/howto/regex.rst:514: starttagopen = re.compile( ... ) It might be worth expanding a bit on this. Compiling regex at module-level causes an overhead at import time that might or might not matter. The re module also has a cache, so even if the regex are not compiled manually they get cached (unless the cache is full and they are removed from there). Deciding what to do is a judgment call, but mentioning these things might help taking a decision. http://bugs.python.org/review/18562/