Watch it together with the written tutorial to deepen your understanding: Using the Python not Operator Python’s not operator allows you to invert the truth value of Boolean expressions and objects. We also saw how check if a list is empty by comparing it to an empty list. Remove ads Watch Now This tutorial has a related video course created by the Real Python team. We saw how to check if a list is empty by using the not operator, and the len() function. In this article, we saw how to check if a list is empty in Python by using three different methods. You can play around with the code by adding elements to the list to see which if.else statement gets executed. In the example above, we compared the people_list list to an empty list: if people_list = # Your list is empty How To Check if a List Is Empty in Python By Comparing To an Empty ListĪn interesting way to check if a list is empty is by comparing it to another empty list. Now that we know that the length of an empty list is 0, we use it to check if a list is empty: people_list = You can also get the length of an empty list: people_list = In the above syntax, we saw that we can define not equal to in two ways in Python using or is not in the expressions or conditions and returns the Boolean value True or False having operands with the same type on both sides of the operator. Using the len() function, we printed the length of the people_list list which had four elements. You can use the len() function in Python to return the number of elements in a data structure. How To Check if a List Is Empty in Python Using the len() Function Check if the strA is empty : The string is. If the values compared are not equal, then a value of false is returned. If the values compared are equal, then a value of true is returned. It returns either true or false depending on the result of the operation. strA ''print ('Check if the strA is empty : ', end'') print ('The string is empty') print ('No it is not empty') Output. The not equal operator is a relational or comparison operator that compares two or more values (operands). So, to check if a string is empty or not we can just apply not operator with it i.e. The not operator in Python checks the string with just spaces to be non-empty, which should not practically be True. An empty string in python is equivalent to False in python. In the code above, we used an if statement and the not operator to check if the people_list was empty. Method 1: Checking empty string using not operator. You can check if a collection is empty using the logic above. Not returns true when an operand is false, and false if an operand is true. The not operator in Python is used for logical negation. How To Check if a List Is Empty in Python Using the not Operator In this article, you'll learn how to check if a list is empty by: But you can't loop/iterate through a list if it has no elements in it. In some cases, you have to iterate through and perform an operation on the elements of a list. For example, any code inside the following conditional block will not execute because the value of varA (null) does not equals the value of varB (the empty. A list is one of the data structures in Python that you can use to store a collection of variables.
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