Why is my python regular expression finding matches, but only giving empty values?-CodePudding

I have a working regular expression that is used to pull 'cid' image references out of the body of an email. I have tested this regex successfully with .NET and regex101.com. It is successful in both instances. When I try in Python, I get the expected number of matches, but they are all empty strings. Code is below.

x = re.findall(r"\*?cid\:(.*?)[a-zA-Z0-9\-.@] .*?", msg.body)
for s in x:
    print(len(s))

Output:

The top five lines are the expected matches. The bottom lines are the output from the code above.

Here it is working on regex101.com

What am I missing?

CodePudding user response：

findall() is capturing you inner regex group in parenthesis. To avoid this, include ?: in you regex as:

x = re.findall(r"\*?cid\:(?:.*?)[a-zA-Z0-9\-.@] .*?", x, flags=0)