Python Program to Find the Least Frequent Character in a String

Give the string the task is to print the least frequent character in a string in Python.

Examples:

Example1:

Input:

Given string =zzzyyddddeeeee

Output:

The least frequency character in the given string zzzyyddddeeeee is [ y ]

Example2:

Input:

Given string =btechgeeks

Output:

The least frequency character in the given string btechgeeks is [ b ]

Program to Find the Least Frequent Character in a String in Python

Below are the ways to print the least frequent character in a string in Python.

Method #1: Using Counter() (Hashing , Static Input)

Approach:

  • Import the Counter() function from collections using the import keyword.
  • Give the string a static input and store it in a variable.
  • Calculate the frequency of all the given string elements using the Counter() function which returns the element and its frequency as key-value pair and store this dictionary in a variable(say elementsfrequency)
  • Calculate the minimum frequency character in the given string using the min() and “get” function and store it in a variable.
  • Print the least frequency character in the given string by printing the above variable.
  • The Exit of the Program.

Below is the implementation:

# Import the Counter() function from collections using the import keyword.
from collections import Counter
# Give the string a static input and store it in a variable.
gvnstrng = 'zzzyyddddeeeee'
# Calculate the frequency of all the given string elements
# using the Counter() function which returns the element
# and its frequency as key-value pair and store this
# dictionary in a variable(say elementsfrequency)
elementsfrequency = Counter(gvnstrng)
# Calculate the minimum frequency character in the given string
# using the min() and "get" function and store it in a variable.
minfreqchar = str(min(elementsfrequency, key=elementsfrequency.get))
# Print the least frequency character in the given string
# by printing the above variable.
print('The least frequency character in the given string',
      gvnstrng, 'is [', minfreqchar, ']')

Output:

The least frequency character in the given string zzzyyddddeeeee is [ y ]

Method #2: Using Counter() (Hashing , User Input)

Approach:

  • Import the Counter() function from collections using the import keyword.
  • Give the string a user input using the input() function and store it in a variable.
  • Calculate the frequency of all the given string elements using the Counter() function which returns the element and its frequency as key-value pair and store this dictionary in a variable(say elementsfrequency)
  • Calculate the minimum frequency character in the given string using the min() and “get” function and store it in a variable.
  • Print the least frequency character in the given string by printing the above variable.
  • The Exit of the Program.

Below is the implementation:

# Import the Counter() function from collections using the import keyword.
from collections import Counter
# Give the string a static input and store it in a variable.
gvnstrng = input('Enter some random string = ')
# Calculate the frequency of all the given string elements
# using the Counter() function which returns the element
# and its frequency as key-value pair and store this
# dictionary in a variable(say elementsfrequency)
elementsfrequency = Counter(gvnstrng)
# Calculate the minimum frequency character in the given string
# using the min() and "get" function and store it in a variable.
minfreqchar = str(min(elementsfrequency, key=elementsfrequency.get))
# Print the least frequency character in the given string
# by printing the above variable.
print('The least frequency character in the given string',
      gvnstrng, 'is [', minfreqchar, ']')

Output:

Enter some random string = btechgeeks
The least frequency character in the given string btechgeeks is [ b ]

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