hi i am using tihs code to find words start with e but it is`t work

code

import re
a="bitte gebe eine nummer bein:"
result=re.sub(r"(\s(e).*\s$)","lol",a,count=1)
print(result)

the output i expect

bitte gebe lol nummer bein

CodePudding user response：

$ matches the end of the string/line in regex (Python Documentation). Your regex would only match a word starting with e that happens to have a space after it and the end of the string right after (for example "eins zwei eine " would work).

In addition, .* is greedy and will consume the rest of your string. You will also need to put spaces around your replacement string for the desired output. So you want something like this:

import re

a = "bitte gebe eine nummer bein:"
result = re.sub(r"(\s(e)\w \s)", " lol ", a, count=1)
print(result)

\w will match [a-zA-Z0-9_] as many as times as possible and will stop at a space to avoid consuming the rest of the string.