Regex function to return string between 2 characters

abalo006

I'm trying to create a regex function that gives me the string between 2 characters

I have the string below

word1_word2_word3_word4_word5_word6_word7_word8_length_string.txt

and I'm trying to return everything after the 7th instance of "_" and before ".txt"

Desired output: word8_length_string

is there a way to use a regex function / regex tool to accomplish this?

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Operating system used: windows

louisbarjon

Hello,

What is exactly your context ?
If you are using a prepare recipe you can use a formula step and use this regular expression:

match(your_column_name, '^(?:[^_]*_){7}(.*)\.txt$')[0]

Note that this regexp explicitly does what you describe, it really counts 7 instances of _ then return everything before .txt

More info about the formula processor here

If you are in a python code recipe, the same regular expression will work as well.

Louis

AdrienL

Some alternatives:

• For the regex, it really depends on what the contraints are. For instance, ^.*_(.+)\.\w+$ would match between the last _ and the extension, see (and edit, explain, play with) the test cases and regex here
• For the tool, you can use many things depending on the need:
  • a python recipe
  • a step in a data preparation recipe, with multiple possibilities
    • python step
    • formula step (as suggested by Louis)
    • text extraction step (probably the simplest for a simple need), with its
  • more exotic options