I am trying to replace a string in Python 3 using regex. I need the string in s1 to be completely replaced with an empty string.
s1 = "/* 123 */" # Pattern /* n */ where n can be any integer
s2 = re.sub(r'/*\s*\d+\s*/',"",s1)
print(s2)
Output(Actual) - /* 123 */ # nothing happens
Output (Expected) - BLANK
* is a meta character, you need to escape it if you want to match a literal * character. You are also missing the literal * character just before the closing /:
s2 = re.sub(r'/\*\s*\d+\s*\*/', "", s1)
Your code was matching zero or more / characters, and zero or more \s spaces, but not any of the literal * characters at the start and end of the comment.
Demo:
>>> import re
>>> s1 = "/* 123 */"
>>> re.sub(r'/\*\s*\d+\s*\*/', "", s1)
''
\S+ all no space characters,\s+ space.
[31]: re.sub(r'\S+|\s+', "", s1)
Out[31]: ''
