Python正则表达式：如何将数字与非数字匹配？

Question

I want split number with another character.

Example

Input:

we spend 100year

Output:

we speed 100 year

Input:

today i'm200 pound

Output

today i'm 200 pound

Input:

he maybe have212cm

Output:

he maybe have 212 cm

I tried re.sub(r'(?<=\\S)\\d', ' \\d', string) and re.sub(r'\\d(?=\\S)', '\\d ', string) , which doesn't work.

Answer 1

This will do it:

ins='''\
we spend 100year
today i'm200 pound
he maybe have212cm'''

for line in ins.splitlines():
    line=re.sub(r'\s*(\d+)\s*',r' \1 ', line)
    print line

Prints:

we spend 100 year
today i'm 200 pound
he maybe have 212 cm

Same syntax for multiple matches in the same line of text:

>>> re.sub(r'\s*(\d+)\s*',r' \1 ', "we spend 100year + today i'm200 pound")
"we spend 100 year + today i'm 200 pound"

The capturing groups (generally) are numbered left to right and the \\number refers to each numbered group in the match:

>>> re.sub(r'(\d)(\d)(\d)',r'\2\3\1','567')
'675'

If it is easier to read, you can name your capturing groups rather than using the \\1 \\2 notation:

>>> line="we spend 100year today i'm200 pound"
>>> re.sub(r'\s*(?P<nums>\d+)\s*',r' \g<nums> ',line)
"we spend 100 year today i'm 200 pound"

Answer 2

This takes care of one case:

>>> re.sub(r'([a-zA-Z])(?=\d)',r'\1 ',s)
'he maybe have 212cm'

And this takes care of the other:

>>> re.sub(r'(?<=\d)([a-zA-Z])',r' \1',s)
'he maybe have212 cm'

Hopefully someone with more regex experience than me can figure out how to combine them ...