Regex matching except whitespace in Python

Question

I am looking to match on a white space followed by anything except whitespace [i.e. letters, punctuation] at the start of a line in Python. For example:

 ` a`  = True
 ` .` = True
 `  a`  = False    [double whitespace]
 `ab` = False      [no whitespace]

The rule re.match(" \w") works except with punctuation - how do i include that?

@JavaNut13 - thanks!! - and sorry, should have been able to figure that myself! — kyrenia
– kyrenia, Commented Oct 12, 2015 at 1:19
"unlike regex in other languages, i couldn't find an option in Python for everything except whitespace" - oh really? well, you need the same syntax. docs.python.org/2/library/re.html \S is right below \s — Karoly Horvath
– Karoly Horvath, Commented Oct 12, 2015 at 1:22

spenibus · Accepted Answer · 2015-10-12 01:35:38Z

13

Remember the following:

\s\S

\s is whitespace
\S is everything but whitespace

edited Oct 12, 2015 at 1:35

spenibus

4,41911 gold badges28 silver badges36 bronze badges

answered Oct 12, 2015 at 1:20

psla

3163 silver badges7 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Sergey · Accepted Answer · 2015-10-12 02:36:27Z

1

import re

r = re.compile(r"(?<=^\s)[^\s]+.*")

print r.findall(" a")
print r.findall(" .")
print r.findall("  a")
print r.findall("ab")

output:

['a']
['.']
[]
[]

regex explanation:

(?<=^\s) - positive lookbehind, matches whitespace at the beginning of string
[^\s]+ - any non whitespace character repeated one or more times
.* - any character repeated zero or more times

answered Oct 12, 2015 at 2:36

Sergey

3412 silver badges9 bronze badges

Collectives™ on Stack Overflow

Regex matching except whitespace in Python

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related