Python Exercise: Unique elements from a list

Last update on April 22 2025 12:58:09 (UTC/GMT +8 hours)

8. Return a New List with Distinct Elements from a List

Write a Python function that takes a list and returns a new list with distinct elements from the first list.

Sample Solution:

Python Code:

# Define a function named 'unique_list' that takes a list 'l' as input and returns a list of unique elements
def unique_list(l):
    # Create an empty list 'x' to store unique elements
    x = []
    
    # Iterate through each element 'a' in the input list 'l'
    for a in l:
        # Check if the element 'a' is not already present in the list 'x'
        if a not in x:
            # If 'a' is not in 'x', add it to the list 'x'
            x.append(a)
    
    # Return the list 'x' containing unique elements
    return x

# Print the result of calling the 'unique_list' function with a list containing duplicate elements
print(unique_list([1, 2, 3, 3, 3, 3, 4, 5]))

Sample Output:

[1, 2, 3, 4, 5]

Explanation:

In the exercise above the code defines a function named "unique_list()" that takes a list as input and returns a new list containing only the unique elements from the input list. It uses a loop to iterate through the input list and checks whether each element is already present in the new list 'x'. If an element is not found in 'x', it appends it to 'x'. Finally, it demonstrates the function by calling it with a list of duplicate elements [1, 2, 3, 3, 3, 3, 4, 5] and prints the resulting list with unique elements.

Pictorial presentation:

Python exercises: Unique elements from a list.

Flowchart:

For more Practice: Solve these Related Problems:

Write a Python function that converts a list to a set and then back to a list to remove duplicates.
Write a Python function that iterates over a list and appends items to a new list only if they have not been encountered before.
Write a Python function that uses dictionary keys to preserve order while filtering out duplicate elements from a list.
Write a Python function that uses list comprehension along with a helper set to filter out duplicates from a list.

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Python Code Editor:

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