Question

Given the code:

import clr
clr.AddReference('System')

from System.Text.RegularExpressions import *

def ReplaceBlank(st):
    return Regex.Replace(
        st,r'[^a-z\s](\s+)[^a-z\s]',
        lambda s:s.Value.Replace(' ', ''),RegexOptions.IgnoreCase)

I expect the input ABC EDF to return ABCDEF but it doesn’t work, what did I do wrong?

Answer 1

[^a-z\s] with ignore-case flag set matches anything other than letters and whitespace characters. ^ at the beginning of a character class (the thing between []) negates the character class.

To replace blanks, you can simply replace \s+ with empty strings or, if you need to match only letters replace

(?<=[a-z])\s+(?=[a-z])

with an empty sting. The second regex will match string of whitespaces between two letters; to account for beginning/end of strings, use

(?<=(^|[a-z]))\s+(?=($|[a-z]))

or

\b\s+\b  

The second one will match spaces between two word boundaries, which include symbol chars like period, comma, hyphen etc.