Question

I’m trying to search a string for numbers, and when finding them, wrap some chars around them, e.g.

a = "hello, i am 8 years old and have 12 toys"
a = method(a)
print a
"hello, i am \ref{8} years old and have \ref{12} toys"

I’ve looked at the re (regular expression) library, but cannot seem to find anything helpful… any cool ideas?

Answer 1

This is pretty basic usage of the .sub method:

numbers = re.compile(r'(\d+)')

a = numbers.sub(r'\ref{\1}', a)

The parethesis around the \d+ number pattern create a group, and the \1 reference is replaced with the contents of the group.

>>> import re
>>> a = "hello, i am 8 years old and have 12 toys"
>>> numbers = re.compile(r'(\d+)')
>>> a = numbers.sub(r'\\ref{\1}', a)
>>> print a
hello, i am \ref{8} years old and have \ref{12} toys