Python: Select a string from a given list of strings with the most unique characters

Last update on April 17 2025 13:03:04 (UTC/GMT +8 hours)

String with Most Unique Characters

Write a Python program to select a string from a given list of strings with the most unique characters.

Input:
['cat', 'catatatatctsa', 'abcdefhijklmnop', '124259239185125', '', 'foo', 'unique']
Output:
abcdefhijklmnop

Input:
['Green', 'Red', 'Orange', 'Yellow', '', 'White']
Output:
Orange

Visual Presentation:

Python: Select a string from a given list of strings with the most unique characters.

Sample Solution-1:

Python Code:

# License: https://bit.ly/3oLErEI

# Define a function named 'test' that takes a list of strings 'strs' as input
def test(strs):
    # Use the max function to find the string with the most unique characters
    # The key argument specifies a lambda function that calculates the length of the set of characters in each string
    return max(strs, key=lambda x: len(set(x)))

# Assign a specific list of strings 'strs' to the variable
strs = ['cat', 'catatatatctsa', 'abcdefhijklmnop', '124259239185125', '', 'foo', 'unique']

# Print the original list of strings 'strs'
print("Original list:")
print(strs)

# Print a message indicating the operation to be performed
print("Select a string from the said list of strings with the most unique characters:")

# Print the result of the test function applied to the 'strs' list
print(test(strs))

# Assign another specific list of strings 'strs' to the variable
strs = ['Green', 'Red', 'Orange', 'Yellow', '', 'White']

# Print the original list of strings 'strs'
print("\nOriginal list:")
print(strs)

# Print a message indicating the operation to be performed
print("Select a string from the said list of strings with the most unique characters:")

# Print the result of the test function applied to the 'strs' list
print(test(strs))

Sample Output:

Original list:
['cat', 'catatatatctsa', 'abcdefhijklmnop', '124259239185125', '', 'foo', 'unique']
Select a string from the said list of strings with the most unique characters:
abcdefhijklmnop

Original list:
['Green', 'Red', 'Orange', 'Yellow', '', 'White']
Select a string from the said list of strings with the most unique characters:
Orange

Flowchart:

Sample Solution-2:

Python Code:

# License: https://bit.ly/3oLErEI

# Define a function named 'test' that takes a list of strings 'strs' as input
def test(strs):
    # Initialize variables to track the largest set, its length, and the corresponding string
    largest_set = {}
    n = 0
    largest = None
    
    # Iterate over each phrase in the list of strings 'strs'
    for phrase in strs:
        # Calculate the difference in lengths between the current largest set and the set of the current phrase
        diff = len(largest_set) - len(set(phrase))
        
        # Compare the differences and update variables accordingly
        if diff < 0:
            largest_set = set(phrase)
            largest = phrase
            n = len(largest_set)
        elif diff == 0:
            if n < len(set(phrase)):
                largest_set = set(phrase)
                largest = phrase
                n = len(largest_set)
        else:
            pass
    
    # Return the string with the most unique characters
    return largest

# Assign a specific list of strings 'strs' to the variable
strs = ['cat', 'catatatatctsa', 'abcdefhijklmnop', '124259239185125', '', 'foo', 'unique']

# Print the original list of strings 'strs'
print("Original list:")
print(strs)

# Print a message indicating the operation to be performed
print("Select a string from the said list of strings with the most unique characters:")

# Print the result of the test function applied to the 'strs' list
print(test(strs))

# Assign another specific list of strings 'strs' to the variable
strs = ['Green', 'Red', 'Orange', 'Yellow', '', 'White']

# Print the original list of strings 'strs'
print("\nOriginal list:")
print(strs)

# Print a message indicating the operation to be performed
print("Select a string from the said list of strings with the most unique characters:")

# Print the result of the test function applied to the 'strs' list
print(test(strs))

Sample Output:

Original list:
['cat', 'catatatatctsa', 'abcdefhijklmnop', '124259239185125', '', 'foo', 'unique']
Select a string from the said list of strings with the most unique characters:
abcdefhijklmnop

Original list:
['Green', 'Red', 'Orange', 'Yellow', '', 'White']
Select a string from the said list of strings with the most unique characters:
Orange

Flowchart:

For more Practice: Solve these Related Problems:

Write a Python program to select the string from a list that has the highest count of unique characters.
Write a Python program to compare the uniqueness of characters in each string and return the one with the maximum unique count.
Write a Python program to iterate over a list and compute the unique character set size for each string, selecting the largest.
Write a Python program to use set operations to determine which string in a list contains the most distinct characters.

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Python Code Editor :

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