Python code to print common characters of two Strings in alphabetical order

PythonProgrammingServer Side Programming

Two user input strings are given, our task is to print all the common characters in alphabetical order.


string1: python
string2: program
Output: op


The letters that are common between the two strings are o (1 times), p (1 time)


Step 1: first we take two input string.
Step 2: next we will do to convert these two strings into counter dictionary.
Step 3: Now find common elements between two strings using intersection ( ) property.
Step 4: Resultant will also be a counter dictionary having common elements as keys and their common frequencies as value.
Step 5: Use elements () method of the counter dictionary to expand the list of keys by their frequency number of times.
Step 6: sort list in ascending order to print a resultant string in alphabetical order.
Step 7: join characters without space to produce resultant string.

Example Code

from collections import Counter
def common(str1,str2):
   d1 = Counter(str1)
   d2 = Counter(str2)
   cdict = d1 & d2
   if len(cdict) == 0:
      print -1
   cchars = list(cdict.elements())
   cchars = sorted(cchars)
   print ("Common characters are ::>",''.join(cchars) )
      # Driver program
   if __name__ == "__main__":
      s1 = input("Enter first string")
      s2 = input("Enter second string")
common(s1, s2)


Enter first string python
Enter second string program
Common characters are ::> op
Published on 26-Sep-2018 06:57:49