Python: Find and group all anagrams in a list

Last update on March 28 2025 13:01:23 (UTC/GMT +8 hours)

26. Find All Anagrams and Group Them from a List of Strings

Write a Python program to find all the anagrams and group them together from a given list of strings. Use the Python data type.

Sample Solution:

Python Code:

# Define a function 'group_anagrams' that takes a list of strings 'strs' as input.
def group_anagrams(strs):
    # Create an empty dictionary 'result' to store grouped anagrams.
    result = {}
    
    # Iterate over each string 's' in the input list 'strs'.
    for s in strs:
        # Sort the characters of the string 's' and join them to create a sorted string.
        sorted_string = ''.join(sorted(s))
        
        # Check if the sorted string exists as a key in 'result'.
        if sorted_string in result:
            # If it exists, append the original string 's' to the existing list of anagrams.
            result[sorted_string].append(s)
        else:
            # If it doesn't exist, create a new entry with the sorted string as the key and a list containing 's' as the value.
            result[sorted_string] = [s]
    
    # Convert the values of the 'result' dictionary (lists of anagrams) to a list and return it.
    return list(result.values())

# Define a list of strings 'strs' for testing.
strs = ['eat', 'cba', 'tae', 'abc', 'xyz']
print("Original list of strings:")
print(strs)

# Call the 'group_anagrams' function and print the result for the list of strings.
print("Find and group all anagrams in the said list:")
print(group_anagrams(strs))

# Repeat the process for a different set of strings.
strs = ['restful', 'forty five', 'evil', 'over fifty', 'vile', 'fluster']
print("\nOriginal list of strings:")
print(strs)

# Call the 'group_anagrams' function and print the result for the list of strings.
print("Find and group all anagrams in the said list:")
print(group_anagrams(strs)) 

Sample Output:

Original list of strings:
['eat', 'cba', 'tae', 'abc', 'xyz']
Find and group all anagrams in the said list:
[['eat', 'tae'], ['cba', 'abc'], ['xyz']]

Original list of strings:
['restful', 'forty five', 'evil', 'over fifty', 'vile', 'fluster']
Find and group all anagrams in the said list:
[['restful', 'fluster'], ['forty five', 'over fifty'], ['evil', 'vile']]

Flowchart:

For more Practice: Solve these Related Problems:

• Write a Python program to group a list of strings into lists of anagrams using sorting of characters as the key.
• Write a Python program to use a dictionary to map sorted tuples of letters to lists of words that are anagrams.
• Write a Python program to iterate over a list of words and group them into anagram clusters using collections.defaultdict.
• Write a Python program to implement a function that returns groups of anagrams from a list of strings in sorted order.

Python Code Editor:

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