Quotes in strings with python

December 15, 2005

AK has a rant about python and why it’s not his favourite language. He writes:

   1. # replace *text* by '''text'''.   2. p = re.compile('*([^*]+)*',re.MULTILINE)   3. text = p.sub(r"""'''\1'''""",text) 
So many quotes, just awful, and so absolutely un-intuitive.

First of all your regex will not work when you don’t escape the asterisks (the blog’s markup has eaten the backslashes?) and maybe I am missing something here, but why should we need multiline (raw) strings for the substitution? It should work with single double quotes.

>>> import re
>>> p = re.compile ('\*([^*]+)\*', re.MULTILINE)
>>> text = "convert the *markup*"
>>> print p.sub(r"'''\1'''", text)
convert the '''markup'''

Is there a better way to enter your string?

>>> s = "'" * 3
>>> print r"%s\1%s" % (s,s)
'''\1'''

IMHO not much better … but the following is an interesting approach (but not really suited for this simple problem):

>>> from string import Template

>>> s = Template('$threesinglequotes\\1$threesinglequotes')
>>> singlequote = "'"
>>> s.substitute(threesinglequotes=singlequote*3)
"'''\\1'''"
>>> p.sub(s.substitute(threesinglequotes=singlequote*3), text)
"convert the '''markup'''"

Hmm, overhead but readable, I’d prefer the simple string above.

BTW, which language supports better syntax to define the string “”’\1”’”?

Category Posted in Python