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python - Regex Matching - A letter not preceded by another letter

What could be regex which match anystring followed by daily but it must not match daily preceded by m?

For example it should match following string

  • beta.daily
  • abcdaily
  • dailyabc
  • daily

But it must not match

  • mdaily or
  • abcmdaily or
  • mdailyabc

I have tried following and other regex but failed each time:

  • r'[^m]daily': But it doesn't match with daily
  • r'[^m]?daily' : It match with string containing mdaily which is not intended
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Just add a negative lookbehind, (?<!m)d, before daily:

(?<!m)daily

The zero width negative lookbehind, (?<!m), makes sure daily is not preceded by m.

Demo


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