I want to take the string 0.71331, 52.25378 and return 0.71331,52.25378 - i.e. just look for a digit, a comma, a space and a digit, and strip out the space.
This is my current code:
coords = '0.71331, 52.25378'
coord_re = re.sub("(\d), (\d)", "\1,\2", coords)
print coord_re
But this gives me 0.7133,2.25378. What am I doing wrong?
2 Answers
You should be using raw strings for regex, try the following:
coord_re = re.sub(r"(\d), (\d)", r"\1,\2", coords)
With your current code, the backslashes in your replacement string are escaping the digits, so you are replacing all matches the equivalent of chr(1) + "," + chr(2):
>>> '\1,\2'
'\x01,\x02'
>>> print '\1,\2'
,
>>> print r'\1,\2' # this is what you actually want
\1,\2
Any time you want to leave the backslash in the string, use the r prefix, or escape each backslash (\\1,\\2).
Python interprets the \1 as a character with ASCII value 1, and passes that to sub.
Use raw strings, in which Python doesn't interpret the \.
coord_re = re.sub(r"(\d), (\d)", r"\1,\2", coords)
This is covered right in the beginning of the re documentation, should you need more info.
