Here are different ways to check if a list is empty in Python:
- Using not operator(Boolean context)
- Using len() function
- Comparing with an Empty List
- Using the PEP 8 recommended method
- Using != operator
- Using NumPy Module
Method 1: Using not operator(Boolean context)
The Pythonic and concise way is to use the not operator. You can simply check the list directly in an if statement, and it returns true if the list is empty, otherwise false.
Visual Representation
Example
players_list = []
if not players_list:
print("Player list is empty")
else:
print("Player list is not empty")
players_list_2 = ['Ronaldo']
if not players_list_2:
print("Player list is empty")
else:
print("Player list is not empty")
Output
Player list is empty
Player list is not empty
Method 2: Using len() Function
The len() function is used to find the number of elements in a list. If it returns zero, that means the list is empty; otherwise, it is not.
Visual Representation
Example
players_list = []
if len(players_list) == 0:
print("Player list is empty")
else:
print("Player list is not empty")
players_list_2 = ['Ronaldo']
if len(players_list_2) == 0:
print("Player list is empty")
else:
print("Player list is not empty")
Output
Player list is empty
Player list is not empty
Method 3: Comparing with an Empty List
You can compare the list directly with an empty list [].
Visual Representation
Example
players_list = []
if players_list == []:
print("Player list is empty")
else:
print("Player list is not empty")
players_list_2 = ['Ronaldo']
if players_list_2 == []:
print("Player list is empty")
else:
print("Player list is not empty")
Output
Player list is empty
Player list is not empty
Method 4: Using the PEP 8 recommended method
According to PEP 8(the style guide for Python), the Pythonic method to check for an empty list is to take advantage of the fact that empty lists are considered falsy.
Visual Representation
Example
players_list = []
if players_list:
print("Player list is not empty")
else:
print("Player list is empty")
Output
Player list is empty
Method 5: Using != operator
The != (not equal) operator checks if a list is not equal to an empty list and returns True if it is not empty, and False otherwise.
Example
players_list = []
if players_list != []:
print("Player list is not empty")
else:
print("Player list is empty")
Output
Player list is empty
Method 6: Using NumPy Module
First, you need to convert the list to a NumPy array and then check if the size attribute is zero.
Example
import numpy as np
players_list = []
np_array = np.array(players_list)
if np_array.size == 0:
print("Player list is empty")
else:
print("Player list is not empty")
Output
Player list is empty
Alternatively, you can use the numpy.size() function directly on the list.
Krunal Lathiya is a seasoned Computer Science expert with over eight years in the tech industry. He boasts deep knowledge in Data Science and Machine Learning. Versed in Python, JavaScript, PHP, R, and Golang. Skilled in frameworks like Angular and React and platforms such as Node.js. His expertise spans both front-end and back-end development. His proficiency in the Python language stands as a testament to his versatility and commitment to the craft.