# Get unique values from a list # Using collections.Counter() lists = [0, 2, 4, 6, 2, 4, 8] def unique(lists): # Print directly by using * symbol print(*Counter(lists)) unique(lists)

Yields below output.

# Output: 0 2 4 6 8

5. Get Unique Values Using Python list.append()

Alternatively, you can use the append() function along with for loop to get the unique values from a list. First initializes an empty list and iterate the given list of values using for loop. For every iteration, the obtained item will check if it is present in the empty list or not. If it is not it will add to the empty list using the append() function. Finally, iterate an empty list that contains unique values using for loop and print them.

# Initialize the list lists = [10, 20, 10, 30, 40, 40, 50, 30] # Get unique values from a list # Using append() function empty_list = [] for item in lists: if item not in empty_list: empty_list.append(item) print("Unique values of the list:\n") for item in empty_list: print(item)

Yields below output.

# Output: Unique values of the list:

6. Using numpy.unique() Function

You can also use the unique() function of numpy module in Python to get the unique values from a list. The numpy.unique() function takes an array as its parameter and returns an array containing only the unique values of the input array.

Before going to use numpy.unique() function we need to convert the list to a NumPy array using the np.array() function. Let’s apply unique() function over the array and get the unique values from it.

# Import the numpy module import numpy as np # Initialize the list lists = [2, 4, 2, 3, 4, 1, 5] # Convert list to NumPy array arr = np.array(lists) # Get unique values from a list # Using numpy.unique() function print("Unique values of list:\n", np.unique(arr))

Yields below output.

# Output: Unique values of the list: [1 2 3 4 5]

7. Get Unique Values from a List Using Pandas

You can use the pandas module to get unique values from a list, for example, the unique() function takes a list as an argument, converts it to a pandas Series object , and drops the duplicate values using the drop_duplicates() method, and then converts the resulting Series object back to a list using the tolist() method. The unique values are then printed using the print() function in a loop.

# Import pandas import pandas as pd # Initialize the list lists = [1, 2, 3, 2, 3, 4, 1, 5] # Get unique values from a list # Using pandas def unique(lists): unique_list = pd.Series(lists).drop_duplicates().tolist() for x in unique_list: print(x) unique(lists)

Yields below output.

# Output:

8. Using Operator.countOf() Method

Finally, you can also use the operator.countOf() method to get unique values. The input list is defined as lists with some elements. The function unique() takes this list as an argument. Inside the function, an empty list unique_list is initialized to store the unique elements. The fo r loop iterates over each element in the input list lists.

The op.countOf() method checks if the current element x already exists in the unique_list or not . If the count of x in unique_list is zero, then it means x is a unique element and is appended to unique_list . Finally, the function prints all the unique elements in the unique_list using another for loop.

# Import module import operator as op # Using Operator.countOf() method lists = [1, 2, 3, 2, 3, 4, 1, 5] def unique(lists): # initialize a null list unique_list = [] for x in lists: # check if exists in unique_list or not if op.countOf(unique_list, x) == 0: unique_list.append(x) for x in unique_list: print(x) unique(lists)

Yields the same output as above.

9. Conclusion

In this article, I have explained how to get unique values from a list in Python by using the set() , reduce() , collections.Counter() , append() , numpy.unique() , Pandas , and Operator.countOf() functions with examples. Depending on your need you can use any of these methods.

Happy Learning !!

Related articles

Python list union with example .

How to get negative index of a list?

How to remove first element from list in Python?

Get first N elements of list

How to create a list of tuples in Python?

Ways to Loop Through a List in Python

Select random item from list in Python

How to get the last element of a list

Difference between list append() vs extend()

Convert list of tuples to list of lists in Python

Remove common elements from two lists in Python

Check given object is a list or not in Python

How to get even Integers from Python list?

You may also like reading:

1. Python List sort() Method
2. Convert List to String in Python
3. Count Occurrences of Item in Python List
4. Python List insert() with Examples
5. Find Difference of Lists in Python
6. Python Insert List in Another List
7. Add Element to Front of List in Python
8. Python Append Suffix to List of Strings
9. Python List Slice with Examples
10. Shuffle List in Python with Examples
I am Mallikarjuna an experienced technical writer with a passion for translating complex Python concepts into clear, concise, and user-friendly documentation. Over the years, I have written hundreds of articles in Pandas, NumPy, Python, and I take pride in my ability to bridge the gap between technical experts and end-users by delivering well-structured, accessible, and informative content.