CODEWITHSUNDEEP
pythonregex
Tomic
Tomic

Reputation: 59

Python Regular Expression:Optional

In a file I have following set of data

FX_DETAIL_69#chf4
FX_DETAIL_75#chf1
FX_DETAIL_07#bluXCFG#chf2
FX_DETAIL_99#bluXCFG#chf9
FX_DETAIL_62#chf6

I have written the following regular expression in Python:

FX_DETAIL\_(\d+)\#(\w+)

How can I use the optional option to exclude value .bluXCFG?

Upvotes: 2

Views: 39

Answers (3)

The fourth bird
The fourth bird

Reputation: 163217

You could optionally match all that follows except a newline or the # itself till the next occurrence of # using a negated character class.

FX_DETAIL_(\d+)#(?:[^#\r\n]*#)?(\w+)

Regex demo

Upvotes: 0

Barmar
Barmar

Reputation: 780798

Use (?:#bluXCFG)? to specify an optional group.

FX_DETAIL_(\d+)(?:#bluXCFG)?#(\w+)

BTW, there's no need to escape _ and #, they have no special meaning.

Upvotes: 1

Selcuk
Selcuk

Reputation: 59184

You can use a greedy wildcard (.*) to consume everything until the last #(\w+):

FX_DETAIL_(\d+).*#(\w+)

Upvotes: 3

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