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regexgoogle-colaboratory

What type of regex does Google Colab use for find and replace feature

I am trying to use a Regular Expression in the Find and Replace feature within Google Colab, located in the left side tool bar, but it does not seem to recognize it. Is there a specific Regular expression that Google Colaboratory uses?

I'm trying to find фll occurrences of xtst excluding occurrences xtst_, xtst2_.

Expression I've tried:

  • xtst(?!\_+|\d+)
  • (xtst(?!\_+|\d+))
  • (xtst)(?!\_+|\d+)
  • r"(xtst(?!\_+|\d+))"

This string works, but is incorrect as it's looking for all occurrences of x,t,s,t everywhere.

  • [xtst](?!\_+|\d+)

Test string:

  • xtr, xtst, ytr, ytst =

Result of working RE for the string above would be:

  • xtst

The 1st RE is working fine at regex101.com as well as the 2nd, and 3rd RE.

Solution

  • You should not escape the underscore _, it is a word character, and escaping word characters is not always allowed across regex libraries.

    What you want to match is xtst not followed with either a digit or underscore, so you can use

    xtst(?!_|\d)
xtst(?![\d_])
xtst(?![0-9_])