Working with arrays in Python is a common practice for many developers. However, there can be instances where you need to check if an array is empty.
This knowledge becomes especially important when the array’s content (or lack thereof) dictates the next course of action in your coding sequence. In this tutorial, we will guide you step by step on how to check if an array is empty in Python.
Step 1: Define Your Array
For the sake of this tutorial, we’ll create an empty array. In Python, an array can simply be defined by enclosing a comma-separated sequence in square brackets []. The content of an array is mutable and can contain elements of different data types. Here is an example of how to define an array:
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myArray = [] |
Step 2: Using the len() Function
The simplest and most direct way to check if an array is empty is by using the built-in Python function len(). The len() function returns the number of items in an object. When applied to an array, it returns the number of elements in the array. An empty array will return a length of zero. Here is how to use it:
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if len(myArray) == 0: print("Array is empty") else: print("Array is not empty") |
Step 3: Using the bool() Function
Another way to check if an array is empty in Python is by converting the array into a Boolean context with the bool() function. An empty array will return False when converted to a Boolean context while an array with elements will return True. Here’s how to use it:
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if bool(myArray) == False: print("Array is empty") else: print("Array is not empty") |
Here is the full code:
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myArray = [] #Using len() if len(myArray) == 0: print("Array is empty using len()") else: print("Array is not empty using len()") #Using bool() if bool(myArray) == False: print("Array is empty using bool()") else: print("Array is not empty using bool()") |
Here is the expected output:
Array is empty using len() Array is empty using bool()
Conclusion
As a Python developer, knowing how to check if an array is empty gives you more control over your code’s direction and processes. This tutorial provided steps and examples using len() and bool() functions to check if an array is empty. Practice these methods and combine them with your other Python skills to tackle even more complex tasks. Keep coding!