Regular expression for searching for extra backslashes

Question

I have a text file which contains files locations and addresses (e.g. %Software\Policies\Microsoft\Windows\Safer\CodeIdentifiers\0\Hashes)

However for some of them I have multiple backslashes in a row which I want to get rid off and replace them by only one backslashes .. is there a regular expression that I can use to identify all extra backslashes (more than one in a row) ?

@DeepSpace consider: `'\\\\\\'.replace('\\\\', '\\')`... gives you `'\\\\'` which isn't a single backslash... — Jon Clements, Mar 07 '17 at 08:58

Mustofa Rizwan · Accepted Answer · 2017-03-07T09:12:58.810

0

Try this:

\\{2,}

Replace By:

\\

Demo

Sample Code:

import re
regex = r"\\{2,}"
test_str = r"%Software\\Policies\\\\Microsoft\\Windows\\Safer\\CodeIdentifiers\\0\\Hashes\\"


subst = r"\\"
result = re.sub(regex, subst, test_str, 0)

if result:
    print (result)

Run it

edited Mar 07 '17 at 09:12

answered Mar 07 '17 at 08:55

Mustofa Rizwan

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Is there a reason you use raw string notation for the regex, but not for the teststring or the replacement? – Sebastian Proske Mar 07 '17 at 09:00
@SebastianProske I generated the code, no reason apart ... made it look normal now – Mustofa Rizwan Mar 07 '17 at 09:12
Million thanks exactly what I want, but what does `0` means in here ? `result = re.sub(regex, subst, test_str, 0)` – analeen Mar 07 '17 at 09:16
@analeen #here the fourth argument 0 indicates means replace all... 1 means replace once, 2 means replace twice and ... – Mustofa Rizwan Mar 07 '17 at 09:28

score 0 · Answer 2 · edited May 23 '17 at 12:25

Did you got the chance to look into the python documentation? Regex: you'll need to know:

'*' Causes the resulting RE to match 0 or more repetitions of the preceding RE, as many repetitions as are possible. ab* will match ‘a’, ‘ab’, or ‘a’ followed by any number of ‘b’s.

'?' Causes the resulting RE to match 0 or 1 repetitions of the preceding RE. ab? will match either ‘a’ or ‘ab’.

'\' Either escapes special characters (permitting you to match characters like '*', '?', and so forth), or signals a special sequence. so to check '\' you need to put it as '\'. For example, to match a literal backslash, one might have to write '\\' as the pattern string, because the regular expression must be \, and each backslash must be expressed as \ inside a regular Python string literal.

If you need to know how to use regex in python: Python string.replace regular expression

Regular expression for searching for extra backslashes

2 Answers2