Program to Find All Non Repeated Characters in a String

Python Program to Find All Non Repeated Characters in a String

In the previous article, we have discussed Program to Find Lexicographic Rank of a Given String

Given a string and the task is to find all the Non repeated characters in a given String.

Counter function in Python:

The counter is a set and dict subset. Counter() takes an iterable entity as an argument and stores the elements as keys and the frequency of the elements as a value. So, in collections, if we transfer a string. When you call Counter(), you’ll get a Counter class object with characters as keys and their frequency in a string as values.

Counter() returns a Counter type object (a subclass of dict) with all characters in the string as keys and their occurrence count as values. We’ll use the [] operator to get the occurrence count of the characters from it.

Examples:

Example1:

Input:

Given String = "hello this is btechgeeks"

Output:

In a Given String,{ hello this is btechgeeks } all Non-repeating Characters are:
o b c g k

Example2:

Input:

Given String = "good morning btechgeeks"

Output:

In a Given String,{ good morning btechgeeks } all Non-repeating Characters are:
d m r i b t c h k s

Program to Find All Non-Repeated Characters in a String in Python

Below are the ways to find all the Non repeated characters in a given String:

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

Approach:

  • Import the Counter() function from collections using the import keyword.
  • Give the string as 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 a key-value pair and stores this dictionary in another variable (say strngfreqelements).
  • Traverse in this frequency dictionary using the for loop.
  • Inside the loop, check if the Key has the frequency 1 and key not equal to space using the if conditional statement
  • If the statement is true, then print the value of the key.
  • 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 as static input and store it in a variable.
gven_str = "hello this is btechgeeks"
# Calculate the frequency of all the given string elements using the Counter() function
# which returns the element and its frequency as a key-value pair and stores this
# dictionary in another variable (say strngfreqelements).
strngfreqelements = Counter(gven_str)
print("In a Given String,{", gven_str, "} all Non-repeating Characters are:")
# Traverse in this frequency dictionary using the for loop.
for key in strngfreqelements:
    # Inside the loop, check if the Key has the frequency 1 and key not equal to space
    # using the if conditional statement
    if(strngfreqelements[key] == 1 and key != " "):
     # If the statement is true, then print the value of the key.
        print(key, end=" ")

Output:

In a Given String,{ hello this is btechgeeks } all Non-repeating Characters are:
o b c g k

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

Approach:

  • Import the Counter() function from collections using the import keyword.
  • Give the string as 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 a key-value pair and stores this dictionary in another variable (say strngfreqelements).
  • Traverse in this frequency dictionary using the for loop.
  • Inside the loop, check if the Key has the frequency 1 and key not equal to space using the if conditional statement
  • If the statement is true, then print the value of the key.
  • 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 as user input using the input() function and 
# store it in a variable.
gven_str = 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 a key-value pair and stores this
# dictionary in another variable (say strngfreqelements).
strngfreqelements = Counter(gven_str)
print("In a Given String,{", gven_str, "} all Non-repeating Characters are:")
# Traverse in this frequency dictionary using the for loop.
for key in strngfreqelements:
    # Inside the loop, check if the Key has the frequency 1 and key not equal to space
    # using the if conditional statement
    if(strngfreqelements[key] == 1 and key != " "):
     # If the statement is true, then print the value of the key.
        print(key, end=" ")

Output:

Enter some random String = good morning btechgeeks
In a Given String,{ good morning btechgeeks } all Non-repeating Characters are:
d m r i b t c h k s

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