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Count occurrences of a character in string in Python

Hello everyone! Today we are going to see how can we count the occurrences of a character in a given string using Python.

Python provides a library method count which can be used to count the occurrence of a substring in a given string. Below code snippet takes a character as a substring and returns the count of that in the source string.
# Enter the string in which we need to search 
sentence = input("Enter a string\n")
 
# Enter a string/character which needs to be searched
sub_string = input("Enter the substring to search\n")
 
# Getting the count of the sub string in source string - convert both to lowercase if we want to count irrespective of case
count_of_substring = sentence.lower().count(sub_string.lower())
 
# Print the count of the substring in the source string
print('Count of ' + sub_string + ' in ' + sentence + ' is ' + str(count_of_substring))
The output of this program will be as follows -
>> Enter a string
Help is always given at Hogwarts to those who ask for it
>> Enter the substring to search
h
>> Count of h in Help is always given at Hogwarts to those who ask for it is 4
If you do not wish to use the library method and want to implement your own then you can do this as follows -
def character_count(source_string, character):
 
    # Converting source string and character to lower case to make them case insensitive    
    source_string = source_string.lower()
    character = character.lower()
    
    # Variable to hold the count of character
    count_of_character = 0    
    
    # Iterating through the possible values of i, where i is the starting index of each substring which is of the same length as the substring entered.    
    for i in range(len(source_string) - len(character) + 1):
       
        # Checking if each possible substring of the correct length is equivalent to the substring entered. If so, I increment my count by 1.
     if source_string[i: i + len(character)] == character:
            count_of_character += 1    
 
    return count_of_character
 
 
# Enter the string in which we need to search
sentence = input("Enter a string\n")
 
# Enter a string/character which needs to be searchedsub_string = input("Enter the substring to search\n")
 
# Print the count
print('Count of ' + sub_string + ' in ' + sentence + ' is ' + str(character_count(sentence, sub_string)))
The output of this program will be -
>> Enter a string
Help is always given at Hogwarts to those who ask for it
>> Enter the substring to search
h
>> Count of h in Help is always given at Hogwarts to those who ask for it is 4

Conclusion

In this post, we discussed how to calculate the number of occurrences of a character in a given string.

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