How to check if a string contains a substring in Python?

There are multiple ways to check if a string contains a specific substring.

Using in keyword

You can use in keyword to check if a string contains a specific substring. The expression will return boolean value.

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if 'Stack' in 'BetterStack':
    print('Found it!')
else:
    print('Did not found it!')

The general syntax is the following:

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if substring in string:
    # substring is in string
else
    # substring is not in string

You can also use String.index method to find specific the index in the string where the substring starts.

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string = 'BetterStack'
substring = 'Stack'

try:
    string.index(substring)
except ValueError:
    print('Not found!')
else:
    print('Found it!')

Also, you can use the find function from the String class. This function will return -1 if the substring is not present in the string.

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string = 'BetterStack'
substring = 'Stack'

if string.find(substring) != -1:
    print('Found it!')
else:
    print('Not found!')

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