Python lacks a particular built-in function for directly determining if a list is devoid of elements; however, there are multiple methods to ascertain an empty list utilizing built-in functionalities.
Python includes built-in tools such as len(), not(), and bool(), and by juxtaposing with an empty list. These tools assist in evaluating whether the list is empty or populated. In this article, we will delve deeper into these tools accompanied by examples.
Python presents various built-in tools, and by employing these techniques, you can examine whether a list is empty. Let’s investigate these approaches with illustrative examples:
Technique 1: Employing the len() method to Verify if a List is Empty in Python
The len() function in Python provides the count of items within a list. Thus, when you invoke len(new_list), it simply yields the count of items present in the list. If len(new_list) == 0, it indicates that the list contains no items, categorizing the list as empty.
Syntax:
len(object)
Example 1: When the list contains elements
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Example 2: When the list is devoid of elements
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Output:
Method 2: Employing not() Method to Verify if a List is Empty in Python
The not() method is a logical negation operator. It alters the truth value of a condition or expression.
Not true —> false
Not false —> true
It generates true when the operand is false, and yields false when the operand is true. Typically used to evaluate false statements or negate conditions.
Example:
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Technique 3: By Comparing with an Empty List [ ] to Confirm if a List is Empty in Python
We can determine if the list is vacant by directly comparing it with the empty list ([ ]), simply using the equality operator ( == ).
Illustration:
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Technique 4: Utilizing the bool() Method to Verify if a List is Empty in Python
This bool() method is applied to convert the value into a boolean which can be either True or False. For example, if the list is unoccupied, then bool(0) will yield “False,” whereas if the list carries elements, then bool(1) will yield “True.”
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Here the bool is set to bool(0), leading it to yield "false"; subsequently, it is redefined as bool(1), which results in "true".
Example: bool() with if-else statement
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Note: The distinction between not() and bool() is
not(): primarily utilized for logical negation.
bool(): transforms the value into a boolean (True or False)
Method 5: Utilizing the try-execute approach to verify if a list is empty in Python
Should you attempt to access the initial index of the list when it is empty, an IndexError will be triggered, which must be caught in the except block.
Example:
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Result:
The result will be “List is empty” because the list does not hold any elements.
Summary
In Python, multiple methods exist to verify if a list is empty or not, such as utilizing functions like len(), not(), direct comparison to an empty list [ ], bool(), or a try-except structure. These strategies enhance the readability and efficiency of Python code.
