ReactCHALLENGES

4. Ignore case

re.IGNORECASE is a flag: an option that changes how a pattern matches. It makes letters match regardless of uppercase or lowercase.

  • re.IGNORECASE is a constant from the re module; re.I is its short alias.
  • Pass it by name as flags=... to re.search(), re.findall() or re.sub(). It is also the third positional argument of search() and findall().
  • flags=0 is the default and is case-sensitive.
  • The match keeps the original spelling: searching "python" with the flag finds "Python" and .group() returns "Python".
  • Combine flags with the bitwise OR operator |, for example re.IGNORECASE | re.MULTILINE. One flag is enough for these exercises.

Coming from JavaScript? it is the i flag at the end of a JS regex, /python/i. Python passes it as a separate flags argument instead of inside the pattern.

#01

Search ignoring case

Search for "python" in "Python PYTHON python" with flags=re.IGNORECASE. Print the matched text. The first occurrence wins, even when it uses different capitals.

Print exactly:

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#02

Count every spelling

Use "python" on "Python PYTHON python" with flags=re.IGNORECASE. Store the re.findall() result and print its length.

Print exactly:

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#03

Keep the original spelling

The flag changes what matches, not the text that is returned. Use "python" on "Python PYTHON python" with flags=re.IGNORECASE and print the whole re.findall() list.

Print exactly:

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#04

Use the short alias

re.I is the alias of re.IGNORECASE. Search for "dog" in "Dog DOG dog" using flags=re.I and print the first matched text.

Print exactly:

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