Find index of a character in a Python string

This post will discuss how to find the index of the first occurrence of a character in a string in Python.

1. Using `find()` function

The standard solution to find a character’s position in a string is using the find() function. It returns the index of the first occurrence in the string, where the character is found. It returns -1 when the character is not found.

if __name__ == '__main__':

s = "Techie"

ch = 'e'

index = s.find(ch)

if index != -1:

print(f"Found character '{ch}' at index {index}") # Found character 'e' at index 1

else:

print("Character not found")

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2. Using `index()` function

Alternatively, you can use the index() function, which is similar to the find() function, but raises ValueError when the character is not found.

if __name__ == '__main__':

s = "Techie"

ch = 'e'

try:

index = s.index(ch)

print(f"Found character '{ch}' at index {index}") # Found character 'e' at index 1

except:

print("Character not found")

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3. Using `enumerate()` function

Here’s solution using enumerate() function with generators. This is useful when you need to find the position of all characters in a string that satisfy a condition.

if __name__ == '__main__':

s = "Techie"

ch = 'e'

indexes = [i for i, c in enumerate(s) if c == ch]

print(f"Found character '{ch}' at index {indexes}") # Found character 'e' at index [1, 5]

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4. Using `more_itertools.locate()` function

Finally, you can use the locate() function from the more_itertools Python module to search for characters in a string. It yields each character’s index in the string for which the specified predicate returns True.

import more_itertools

if __name__ == '__main__':

s = "Techie"

ch = 'e'

index = next(more_itertools.locate(s, lambda x: x == ch))

if index != -1:

print(f"Found character '{ch}' at index {index}") # Found character 'e' at index 1

else:

print("Character not found")

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That’s all about finding the index of a character in a string in Python.

Find index of a character in a Python string

1. Using find() function

2. Using index() function

3. Using enumerate() function

4. Using more_itertools.locate() function

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1. Using `find()` function

2. Using `index()` function

3. Using `enumerate()` function

4. Using `more_itertools.locate()` function