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Python Regular Expressions in Python Introduction to Regular Expressions Sets

nuri jeon
nuri jeon
14,376 Points
Posted by nuri jeon
nuri jeon
14,376 Points

Position of the elements in the set! :D I have a question!

Hello! I was watching video about the set and was wondering about the position of this set [-\w\d+.] So I thought it doesn't require any rule when it comes to putting things(ex -, +, . etc) so I did this ---> [\w\d-+.] And... it didn't work :>..... So is there any rule or reason I have to put dash('-') in front of \w\d? or for + and . ? Thanks for help always!

1 Answer

Steven Parker
Steven Parker
231,275 Points
Steven Parker
Steven Parker
231,275 Points

When you use a hyphen inside a character class, it normally combines with the character in front of it and the character after it to represent a range of characters starting at the first and going to the last. For example, "[0-9a-z]" represents any digit or lower-case alpha character.

By putting a hyphen first (or last), you can cause it to represent only itself instead of combining with the others to represent a range.

Julie Luisi
Julie Luisi
1,782 Points

Thank you! I was having issues with this myself and this was a great explanation. Perhaps it should be included in the teachers notes.