How to Iterate Through a Python Array

Arrays are a crucial part of any programming language, and Python is no exception. It provides different ways to work with these arrays in a straightforward manner. In this tutorial, we will guide you on how to iterate through a Python array in several ways.

Step 1: Understanding the Basics

First, it’s important to understand what an array is and why it is used. An Array is a data structure that stores multiple items of the same type. Arrays make it easy to access and manipulate this data. The following example shows the creation of an array in Python:

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import array as arr
numbers = arr.array('i', [1, 2, 3, 4, 5])

Step 2: Iterating Through an Array Using a For Loop

The simplest way to iterate through an array in Python is by using a For loop. This method is the most common in other programming languages as well. Here’s how it’s done:

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for num in numbers:
    print(num)

Output:

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Step 3: Iterating Through an Array Using a While Loop

Another method to iterate through an array is by using a While loop. This might be slightly more complex but it provides more control over the process. Here’s how:

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i = 0
while i < len(numbers):
    print(numbers[i])
    i += 1

Output:

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Step 4: Iterating Using numpy and nditer()

If you’re dealing with large, multidimensional arrays, numpy’s nditer() is incredibly useful. Numpy is a powerful library in Python that deals with numerical operations on arrays. nditer() is a function in Numpy that provides many flexible ways to visit all the elements of an array. To install numpy, use this command pip install numpy.

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import numpy as np
 
numbers_np = np.array([1, 2, 3, 4, 5])
for num in np.nditer(numbers_np):
    print(num)

Output:

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Conclusion

Knowing how to correctly iterate through arrays in Python can drastically increase the efficiency of your code. There are different ways to do this depending on your specific use case. You can use the For loop or While loop, or even make use of the powerful library Numpy.

Full Code:

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import array as arr
import numpy as np
 
numbers = arr.array('i', [1, 2, 3, 4, 5])
 
# using for loop
for num in numbers:
    print(num)
 
# using while loop
i = 0
while i < len(numbers):
    print(numbers[i])
    i += 1
 
# using numpy and nditer()
numbers_np = np.array([1, 2, 3, 4, 5])
 
for num in np.nditer(numbers_np):
    print(num)