if not a:
print("List is empty")
Using the implicit booleanness of the empty list is quite Pythonic.
Top answer 1 of 16
7312
if not a:
print("List is empty")
Using the implicit booleanness of the empty list is quite Pythonic.
2 of 16
1556
The Pythonic way to do it is from the PEP 8 style guide.
For sequences, (strings, lists, tuples), use the fact that empty sequences are false:
# Correct: if not seq: if seq: # Wrong: if len(seq): if not len(seq):
Codedamn
codedamn.com › news › python
Python IsEmpty Function: A Detailed Guide
July 4, 2023 - A: No, the IsEmpty function cannot be used to check if a variable is None. You should use the is operator for this task: my_var = None if my_var is None: print('The variable is None') else: print('The variable is not None') We hope that you now have a clear understanding of how to check if a sequence, collection, or string is empty in Python. Although Python does not have a built-in IsEmpty function, it still offers a variety of ways to perform this task.
Videos
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Flexiple
flexiple.com › python › check-if-list-is-empty-python
Python isEmpty() equivalent – How to Check if a List is Empty in Python - Flexiple - Flexiple
Python isEmpty() equivalent – ... len() function or compare the list directly to an empty list. For example, if len(my_list) 0: or if my_list []: are common methods....
freeCodeCamp
freecodecamp.org › news › how-to-check-if-a-list-is-empty-in-python
Python isEmpty() equivalent – How to Check if a List is Empty in Python
April 19, 2023 - In the example above, we compared the people_list list to an empty list: if people_list == [] You can play around with the code by adding elements to the list to see which if...else statement gets executed. In this article, we saw how to check if a list is empty in Python by using three different methods.
Built In
builtin.com › articles › python-check-if-list-is-empty
Python Check if a List Is Empty: A Guide | Built In
The most common way to test if a list is empty in Python is to use the truth value testing method with the not operator. The len() function is best if you are working with different data structures, while the == operator makes your code easier to read. Here’s an example of the truth value testing method:
Reddit
reddit.com › r/learnpython › how do i check if this list is "empty"?
r/learnpython on Reddit: How do I check if this list is "empty"?
December 8, 2022 -
I'm completely stumped on a computer science assignment because our lecturer has given us zero information. We're supposed to have the user input a list and check if the list is in decreasing order and print a suitable message if it is. That part works fine. However, if the list is "empty" (I'll explain the quotations in a second) then it should print the list is empty.
The problem is that, according to our brief we're supposed to use .split(",") in order to allow the user to separate their numbers with commas. The problem lies in the fact that even if a user hits enter without inputting anything, the list is still '1' long with just an empty string. I've been scouring the web to find out how to check if a list is empty. But all the tutorials have so far just been in relation to actually empty lists (as in, list = []). One did use the all() function to check that all items in the list were strings, which did work and let me print that the list is empty, but broke the original function. Could someone please help me I'm tearing my hair out with this.
--
def checkOrder():
# checks, etc.
integer_list = []
listLength = len(integer_list)
increasing = 0
decreasing = 0
singleValue = 0
# Converting inputted numbers into a split list
userInput = input("Please enter your numbers seperated by a comma (,):")
inputtedStrings = userInput.split(",")
for number in inputtedStrings:
inputtedIntegers = int(number)
integer_list.append(inputtedIntegers)
# Enumerating list
for i, val in enumerate(integer_list[:-1]):
if val <= integer_list[i+1]:
increasing = 1
elif val >= integer_list[i+1]:
decreasing = 1
# Check for a single value
if len(integer_list) == 1:
singleValue = 1
if len(integer_list) == 1 and
print("The list is empty.")
if increasing == 1:
print("The numbers are in increasing order.")
elif decreasing == 1 or singleValue == 1:
print("The numbers are in decreasing order.")
checkOrder()
--
Top answer 1 of 5
8
Well there are a few ways you could deal with this. First would be to check if userInput is an empty string before converting it to a list. Another possibility would be to filter the list to remove all empty strings, eg via a list comprehension. Or you could do the filtering inside the loop you already have that converts to integers. Or, again inside that loop, you could use a counter variable to keep track of how many integers you've converted, and print an error afterwards if it's 0. And so on. The main thing here is that you should get away from thinking about how to code something, but first work out what the steps should be, and only then code it.
2 of 5
3
arr = [''] print(any(arr)) # False any and all are pretty useful built-in functions for iterative boolean checks.
Programiz
programiz.com › python-programming › examples › check-empty-list
Python Program to Check If a List is Empty
It is the most pythonic way of testing emptiness. If you want to learn more about boolean truth value, you can refer to Truth Value Testing. my_list = [] if not len(my_list): print("the list is empty") ... In this example, length of list is used to check if there is any element in the list.
Spark By {Examples}
sparkbyexamples.com › home › python › check if the set is empty in python
Check If the Set is Empty in Python - Spark By {Examples}
May 31, 2024 - If the length of the set is 0, it means the set is empty. In the below example, you can initialize an empty set called myset. The len() function is applied to myset in the if statement.
GeeksforGeeks
geeksforgeeks.org › python › python-check-if-list-empty-not
Check if a list is empty or not in Python - GeeksforGeeks
October 24, 2024 - Lists can be directly evaluated in conditions. Python considers an empty list as False.
Vultr
docs.vultr.com › python › examples › check-if-a-list-is-empty
Python Program to Check If a List is Empty | Vultr Docs
December 6, 2024 - Checking if a list is empty in Python can be performed in several ways, each serving different readability and contextual needs. Using direct boolean evaluation is typically the simplest and most performant. However, explicitly comparing against an empty list or using the len() function might clarify intent in contexts where code readability is paramount.
iO Flood
ioflood.com › blog › python-check-if-list-is-empty
Learn Python: How To Check If a List Is Empty?
June 27, 2024 - You can check if a list is empty in Python by using the not operator with the syntax, if not my_list:. This operator returns True if the list is empty and False otherwise. ... In this example, my_list is an empty list.
TutorialsPoint
tutorialspoint.com › How-to-check-if-a-list-is-empty-in-Python
How to check if a list is empty in Python?
In this article, we will show you how to check if the given input list is empty or NOT using Python. Below are the 5 methods to accomplish this task - ... Assume we have taken an empty list. We will check if the input list is empty or not and return some random message for acknowledgment using different methods as specified above. In the example below, we are going to use the not operator.
Medium
pavolkutaj.medium.com › how-to-check-if-a-list-dict-or-set-is-empty-in-python-as-per-pep8-35d8c64d07d0
How to Check if a List, Dict or Set is Empty in Python as per PEP8 | by Pavol Z. Kutaj | Medium
September 7, 2023 - in effect, it is saying that __nonzero__ is the interface for testing emptiness (__bool__ in python 3 → built-in bool())
Sentry
sentry.io › sentry answers › python › check if a string is empty in python
Check if a string is empty in Python | Sentry
The Problem In Python, what is the most elegant way to check whether a string is empty? The Solution In Python, empty strings are considered equivalent to…
Spark By {Examples}
sparkbyexamples.com › home › python › check if string is empty or not in python
Check if String is Empty or Not in Python - Spark By {Examples}
May 21, 2024 - In the below example, I am using it with a string variable and comparing it with the empty string "", similarly, you can also use it with string literals to check string equality. first="" if "" == first: print("Empty string") else: print("Not empty string") # Output: # Empty string · When you use == operator to check if a string is empty or not, it internally uses Python __eq__() function.
PythonHow
pythonhow.com › how › check-if-a-list-is-empty
Here is how to check if a list is empty in Python
To check if a list is empty in Python, you can use the len() function to check the length of the list. If the length is 0, it means the list is empty. Alternatively, you can use the bool() function to check if a list is empty. This function returns False if the list is empty, and True otherwise.
Codedamn
codedamn.com › news › python
Python List Is Empty: All Methods to Check
July 1, 2023 - Before we dive into the methods to check if a list is empty, let's take a moment to understand what a list is in Python. A list is a data structure that holds an ordered collection of items, i.e., you can store a sequence of items in a list. These items can be of any type—integers, strings, dictionaries, even other lists, and more. # an example of a Python list my_list = ['apple', 'banana', 'cherry']
Apache
spark.apache.org › docs › latest › api › python › reference › pyspark.sql › api › pyspark.sql.DataFrame.isEmpty.html
pyspark.sql.DataFrame.isEmpty — PySpark 4.1.1 documentation
Example 3: Checking if a DataFrame with null values is empty · >>> df_nulls = spark.createDataFrame([(None, None)], 'a STRING, b INT') >>> df_nulls.isEmpty() False · Example 4: Checking if a DataFrame with no rows but with columns is empty · >>> df_no_rows = spark.createDataFrame([], 'id INT, value STRING') >>> df_no_rows.isEmpty() True ·
GeeksforGeeks
geeksforgeeks.org › python › how-to-check-if-variable-is-empty-in-python
How To Check If Variable Is Empty In Python? - GeeksforGeeks
July 23, 2025 - Below are some of the ways by which we can check if the variable is empty in Python or not: ... In this example, the code checks if the length of the list (`my_list`) is zero using `len()`. If the length is zero, it prints "Empty Variable"; ...
Better Stack
betterstack.com › community › questions › how-to-check-if-list-is-empty-in-python
How do I check if a list is empty in Python? | Better Stack Community
In Python, a metaclass is the class of a class. It defines how a class behaves, including how it is created and how it manages its instances.