find(): check if a string has a certain substring in Python

Use the find() method to check if a string has certain substring.

The method returns the index of the first occurrence of the given value.

Remember the index count starts at 0.

phrase = "This is a regular text"

print(phrase.find('This'))

print(phrase.find('regular'))

print(phrase.find('text'))

0
10
18

If the value is not found, the return will be -1.

phrase = "This is a regular text"

print(phrase.find('train'))

-1

You can also choose to begin the search in a specific position and end it in another specific position of the string.

phrase = "This is a regular text"

#look for in 'This is', the rest of the phrase is not included
print(phrase.find('This', 0, 7))

#look for in 'This is a regular'
print(phrase.find('regular', 0, 17))

#look for in 'This is a regul'
print(phrase.find('a', 0, 15))

0
10
8