What '?' Does in regex? | Sololearn: Learn to code for FREE!
New course! Every coder should learn Generative AI!
Try a free lesson
0

What '?' Does in regex?

I have a regular expression : re.search(r"^[+-]?[0-9]*\.[0-9]*

quot;,txt). I don't understand the use of '?'.

regular-expressions
8th May 2020, 4:46 AM
Sagar Singh
Sagar Singh - avatar
4 Answers
+ 4
rodwynnejones is right, I corrected my answer.
8th May 2020, 2:19 PM
Calviղ
Calviղ - avatar
+ 3
I'm sure the "?" means zero or one occurrence.
8th May 2020, 11:46 AM
rodwynnejones
rodwynnejones - avatar
+ 2
edited ? zero or one occurance only of preceding letter [+-]? matches + or - or ''
8th May 2020, 6:39 AM
Calviղ
Calviղ - avatar
0
https://www.sololearn.com/learn/10441/?ref=app
10th May 2020, 4:06 AM
Hima
Hima - avatar

Often have questions like this?

Learn more efficiently, for free:

See all courses
Hot today
Strange narrowing conversion error from FLTK Color to Color Struct, Stroustrup's header Graph.h
0 Votes
no se cual es la respuesta de esta
0 Votes
Can anyone help me with this?
0 Votes
Any good alternative to do this
2 Votes
While loop with input dont work
1 Votes
Hi everyone! I want change div with name "cd" to text(how to add url here)when I click button. No my code not worked. help me.
1 Votes
How to learn fast C?
0 Votes
Python frameworks problem
0 Votes
There is a Python test on Solularen, but I did not find the correct solution.
0 Votes
Coder or Programmers
2 Votes