Calculate Frequency of a Characters in Python

In this post, we will learn how to calculate frequency of a characters in Python using for-loop, while-loop, python dictionary, and dictionary comprehension with detailed explanations and examples.

So let’s start writing a program to calculate the frequency of a characters in Python using all the different ways one by one.

Calculate Frequency of a Characters in Python using for-loop

Few programming concepts you have to know before writing this program:

1. Python String
2. count() method
3. for-loop

Source Code:

my_str = input("Enter your String: ")

tem = "" 
# This temporary (tem) variable helps you to count each character only once 

for char in my_str:
    if char not in tem:
        tem+=char
        print(f"{char} : {my_str.count(char)}") 

Output:

Enter your String: allinpython
a : 1
l : 2
i : 1
n : 2
p : 1
y : 1
t : 1
h : 1
o : 1

Calculate Frequency of a Characters in Python using while-loop

Few programming concepts you have to know before writing this program:

1. Python String
2. count() method
3. while-loop

Source Code:

my_str = input("Enter your String: ")

tem = "" 
# This temporary (tem) variable helps you to count each character only once 

i = 0

while i < len(my_str):
    if my_str[i] not in tem:
        tem+= my_str[i]
        print(f"{my_str[i]} : {my_str.count(my_str[i])}") 
    i+=1 
    

Output:

Enter your String: learn with allinpython
l : 3
e : 1
a : 2
r : 1
n : 3
  : 2
w : 1
i : 2
t : 2
h : 2
p : 1
y : 1
o : 1

Calculate Frequency of a Characters in Python using Dictionary

Few programming concepts you have to know before writing this program:

1. Python Dictionary
2. for-loop
3. count() method
4. update() method

Source Code:

my_str = input("Enter your String: ")
char_count = {}

for char in my_str:
    char_count.update({char: my_str.count(char)})

print(char_count)

Output:

Enter your String: yagyavendra
{'y': 2, 'a': 3, 'g': 1, 'v': 1, 'e': 1, 'n': 1, 'd': 1, 'r': 1}

Note: As the Python dictionary takes the unique keys (there are no duplicate keys present in the dictionary) that’s why each character counts only once.

Calculate Frequency of a Characters in Python using Dictionary Comprehension

Few programming concepts you have to know before writing this program:

1. Python Dictionary &
2. Dictionary Comprehension

Source Code:

string = input("Enter your String: ")

char_counter = {char: string.count(char) for char in string}
print(char_counter)

Output:

Enter your String: aaaalllinnnaaa
{'a': 7, 'l': 3, 'i': 1, 'n': 3}