Program to Find Common Characters between Two Strings

Python Program to Find Common Characters between Two Strings

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In the previous article, we have discussed Python Program to Extract Only Characters from a Given String
Given two strings, the task is to find the common characters between Two Strings.

In this case, we use some of the built-in functions like join(), lower(), sorted() and intersection() methods.

join() :

The string method join()  takes all of the items in an iterable and returns a string after joining them all together. Iterable types include list, tuple, string, dictionary, and set.

lower() :

As the name indicates, It takes a string and converts all uppercase characters to lowercase before returning it.

sorted method() :

The sorted() method is used to orderly sort the elements of a sequence (either ascending or descending).

intersection() method :

The intersection() method is used to find all the elements that are shared by two given sets.

Examples:

Example 1:

Input:

Given First String = Hello Btechgeeks
Given Second String = good morning

Output:

The Common Characters between the above given two Strings =   go

Example 2:

Input:

Given First String = have a nice Day
Given Second String = A special day

Output:

The Common Characters between the above given two Strings = acdeiy

Program to Find Common Characters between Two Strings

Below are the ways to find common characters between two strings.

Method #1: Using intersection Method (Static Input)

Approach:

  • Give the first string as static input, convert the given string into the lower case using the built-in lower() method and store it in a variable.
  • Give the second string as static input, convert the given string into the lower case using the built-in lower() method and store it in another variable.
  • Get the Common characters between both the above-given strings using the built-in intersection() method which is a set method.
  • Sort the above-given string using the built-in sorted() method.
  • Join the above-given string using the built-in join()method.
  • Print all the Common Characters between the above given two Strings.
  • The Exit of the program.

Below is the implementation:

# Give the first string as static input  , convert the given string into lower case
# using built-in lower() method and store it in a variable.
fst_strng = "Hello Btechgeeks".lower()
# Give the  second string as static input , convert the given string into lower case
# using built-in lower() method and store it in another variable.
secnd_strng = "good morning".lower()
# Get the Common characters between both the above given strings using built-in
# intersection() method which is a set method.
# Sort the above given string using  built-in sorted() method.
# Join the the above given string using built-in join()method .
# Print all the Common Characters between the above given two Strings.
print("The Common Characters between the above given two Strings = ",
      ''.join(sorted(set.intersection(set(fst_strng), set(secnd_strng)))))

Output:

The Common Characters between the above given two Strings =   go

Method #2 : Using intersection() Method (User Input)

Approach:

  • Give the first string as User input using the input() function, convert the given string into the lower case using the built-in lower() method and store it in a variable.
  • Give the second string as User input using the input() function, convert the given string into the lower case using the built-in lower() method, and store it in another variable.
  • Get the Common characters between both the above-given strings using the built-in intersection() method which is a set method.
  • Sort the above-given string using the built-in sorted() method.
  • Join the above-given string using the built-in join()method.
  • Print all the Common Characters between the above given two Strings.
  • The Exit of the program.

Below is the implementation:

# Give the first string as User input  using the input() function , convert the given string into lower case
# using built-in lower() method and store it in a variable.
fst_strng = input("Enter some Random String = ").lower()
# Give the  second string as User input  using the input() function, convert the given string into lower case
# using built-in lower() method and store it in another variable.
secnd_strng = input("Enter some Random String = ").lower()
# Get the Common characters between both the above given strings using built-in
# intersection() method which is a set method.
# Sort the above given string using  built-in sorted() method.
# Join the the above given string using built-in join()method .
# Print all the Common Characters between the above given two Strings.
print("The Common Characters between the above given two Strings = ",
      ''.join(sorted(set.intersection(set(fst_strng), set(secnd_strng)))))

Output:

Enter some Random String = have a nice Day
Enter some Random String = A special day
The Common Characters between the above given two Strings = acdeiy

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