Python return list elements

5 Easy Ways To Extract Elements From A Python List

Let’s learn the different ways to extract elements from a Python list When more than one item is required to be stored in a single variable in Python, we need to use lists. It is one of python’s built-in data functions. It is created by using [ ] brackets while initializing a variable.

In this article, we are going to see the different ways through which lists can be created and also learn the different ways through which elements from a list in python can be extracted.

1. Extract Elements From A Python List Using Index

Here in this first example, we created a list named ‘firstgrid’ with 6 elements in it. The print statement prints the ‘1’ element in the index.

firstgrid=["A","B","C","D","E","F"] print(firstgrid[1])

2. Print Items From a List Using Enumerate

Here, we created a variable named ‘vara’ and we filled the elements into the list. Then we used ‘varx’ variable to specify the enumerate function to search for ‘1,2,5’ index positions.

vara=["10","11","12","13","14","15"] print([varx[1] for varx in enumerate(vara) if varx[0] in [1,2,5]])

3. Using Loops to Extract List Elements

You can also Extract Elements From A Python List using loops. Let’s see 3 methods to pull individual elements from a list using loops.

Method 1:

Directly using a loop to search for specified indexes.

vara=["10","11","12","13","14","15"] print([vara[i] for i in (1,2,5)])

Method 2:

Storing list and index positions into two different variables and then running the loop to search for those index positions.

elements = [10, 11, 12, 13, 14, 15] indices = (1,1,2,1,5) result_list = [elements[i] for i in indices] print(result_list)

Method 3:

In this example, we used a different way to create our list. The range function creates a list containing numbers serially with 6 elements in it from 10 to 15.

numbers = range(10, 16) indices = (1, 1, 2, 1, 5) result = [numbers[i] for i in indices] print(result)

4. Using Numpy To View Items From a List

We can also use the popular NumPy library to help us Extract Elements From A Python List. Let’s see how that can be done here using two different methods.

Method 1:

Here, we used the numpy import function to print the index specified in variable ‘sx’ from the elements present in list ‘ax’ using np.array library function.

ax = [10, 11, 12, 13, 14, 15]; sx = [1, 2, 5] ; import numpy as np print(list(np.array(ax)[sx]))

Method 2:

This example uses variable storing index positions and another variable storing numbers in an array. The print statement prints the index positions stored in variable ‘sx’ with respect to a variable containing the list – ‘ay’.

sx = [1, 2, 5]; ay = np.array([10, 11, 12, 13, 14, 15]) print(ay[sx])

5. Extract Elements Using The index function

vara=["10","11","12","13","14","15"] print([vara[index] for index in (1,2,5,20) if 0 
Conclusion
This article explains in great detail the different methods available to search and extract elements from a python list. We learned in this article, how lists are made, the different types of python functions through which elements are extracted from the list. It is hoped that this article might have helped you.
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How to Return List in Python?
Several features make Python an ideal programming language for developers. Python’s ability to return lists is one of its most useful features. A list is a fundamental Python data structure that stores and manipulates data collections.
Python’s return list feature is used to create powerful and efficient code. Considering its importance, this post provides various ways to return a list using the following contents:
Method 1: Using the return Statement
The following examples are used to return a Python list in user-defined function:
def list_func(): list1 = [] for i in range(5): list1.append(i) return list1 num = list_func() print(num)
 
 
The user-defined function named “list_func” is defined.
 
The empty list named “list1” is initialized.
 
The for loop iterates over the specified range and appends each range element to an empty list.
 
The list is returned to the function using the return keyword.
 
The value of the list is accessed by accessing the function.
 
 
 
 
The list has been returned successfully.
 
Example 1: Return a Python List as a String
 
The below code is used to return a Python list as a string:
 
def list_func(list_value): return' '.join([str(i) for i in list_value]) print(list_func(['Joseph', 'Anna', 'Lily']))
 
 
The user-defined function named “list_func” is defined in the program.
 
The “str()” function is used to convert the elements of the list into strings and join them into an empty string using the “join()” function.
 
 
 
 
The list has been returned as a string.
 
Example 2: Return a Python List of Tuples
 
The below code is used to return a Python list of tuples:
 
def list_func(x, y): return list(zip(x, y)) print(list_func(['Joseph', 'Lily', 'Anna'], [15, 32, 45]))
 
 
The function named list_func takes two lists x and y as input.
 
The function retrieves a list of tuples where each tuple contains the corresponding elements of the two input lists.
 
The zip function combines the two lists into a list of tuples. The list function is utilized to convert the result into a list.
 
 
 
 
The list of tuples has been returned successfully.
 
Method 2: Using the List Comprehension
 
The below example code is used to return a list using list comprehension:
 
def list_func(): return [i for i in range(0,10,3)] num = list_func() print(num)
 
 
The list comprehension is used inside the user-defined function to return a list.
 
The list is accessed by accessing the function.
 
 
 
 
The value of the list has been displayed.
 
Method 3: Using Lambda Function
 
The lambda function is defined without a name and using the keyword lambda. The below code is used to return a list by using the lambda function:
 
list_value = lambda : [i for i in range(0, 15, 3)] print(list_value())
 
In the lambda function, the list comprehension is used along with the range() function to create a list of numbers from 0 to 15 with a step of 3.
 
 
 
The list has been returned successfully.
 
Conclusion
 
To return a Python list to the function, the return statement, list comprehension, and lambda function are used in Python. The return statement returns the list individually and with the help of list comprehension. The lambda anonymous function is also used to return a Python list with the help of list comprehension. This guide has provided all the methods to return lists in Python.
 
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Python Return List
 
 
 
A Python function can return any object such as a list. To return a list, first create the list object within the function body, assign it to a variable your_list , and return it to the caller of the function using the keyword operation “ return your_list “.
 
For example, the following code creates a function create_list() that iterates over all numbers 0, 1, 2, …, 9, appends them to the list your_list , and returns the list to the caller of the function:
 
def create_list(): ''' Function to return list ''' your_list = [] for i in range(10): your_list.append(i) return your_list numbers = create_list() print(numbers) # [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
 
Note that you store the resulting list in the variable numbers . The local variable your_list that you created within the function body is only visible within the function but not outside of it.
 
So, if you try to access the name your_list , Python will raise a NameError :
 
>>> print(your_list) Traceback (most recent call last): File "C:\Users\xcent\Desktop\code.py", line 9, in print(your_list) NameError: name 'your_list' is not defined
 
To fix this, simply assign the return value of the function — a list — to a new variable and access the content of this new variable:
 
>>> numbers = create_list() >>> print(numbers) [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
 
Return List with List Comprehension
 
There are many other ways to return a list in Python. For example, you can use a list comprehension statement instead that is much more concise than the previous code—but creates the same list of numbers:
 
def create_list(): ''' Function to return list ''' return [i for i in range(10)] numbers = create_list() print(numbers) # [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
 
List comprehension is a very useful Python feature that allows you to dynamically create a list by using the syntax [expression context] .
 
You iterate over all elements in a given context “ for i in range(10) “, and apply a certain expression, e.g., the identity expression i , before adding the resulting values to the newly-created list.
 
In case you need to learn more about list comprehension, feel free to check out my explainer video:
 
 
 
👉 Recommended Tutorial: Python Zip Function
 
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