How to Read an Array in Python

Reading arrays in Python is an important skill for anybody who wants to start their journey in the wonderful world of programming with Python.

Arrays are basic data structures that hold multiple data items of the same type and are widely used to store, access, and manage data in any programming task.

Python, although doesn’t have a built-in ‘array’ data type, uses the list and other similar data types to perform similar functions as arrays in other languages. Here in this tutorial, we will learn about how to read an array in Python.

Step 1: Creation of array in Python

In Python, we generally use ‘list’ and ‘NumPy’ packages to create and handle array-like structures. A simple example of creating and printing a list is shown below. For using NumPy arrays, you may need to install the NumPy package using pip if you haven’t installed it already. You can install it using the command ‘pip install numpy’ in the terminal.

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# Creation of list
my_list = ['apple', 'banana', 'cherry']
print(my_list)
 
# Creation of NumPy array
import numpy as np
my_array = np.array([1, 2, 3, 4, 5])
print(my_array)

Step 2: Reading elements from an array

We can access elements in an array directly if we know their index. Python uses zero-based indexing, so the first element is at index 0.

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# Accessing first element from list
print(my_list[0])
 
# Accessing first element from NumPy array
print(my_array[0])

Step 3: Reading array using list comprehension

List comprehension provides us with a concise way to create lists based on existing lists (or arrays generated from the NumPy package). It can also be used to access and perform operations on each element of a list.

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# List comprehension on list
print([i for i in my_list])
 
# List comprehension on Numpy array
print([i for i in my_array])

Step 4: Reading array using loop

In Python, iterative reading of an array can be performed by using a ‘for’ loop which accesses each element of an array systematically starting from the first to the last element of the array.

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# Looping over list
for i in my_list:
    print(i)
 
# Looping over Numpy array
for i in my_array:
    print(i)

Step 5: Reading array using an iterator

An iterator is an object that enables us to iterate over the elements of an array.

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# Creating an iterator object from list:
iter_obj = iter(my_list)
 
# Access and print elements from the list
print(next(iter_obj))

Here is the full code:

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# Creation of list
my_list = ['apple', 'banana', 'cherry']
print(my_list)
 
# Creation of NumPy array
import numpy as np
my_array = np.array([1, 2, 3, 4, 5])
print(my_array)
 
# Accessing first element from list
print(my_list[0])
 
# Accessing first element from NumPy array
print(my_array[0])
 
# List comprehension on list
print([i for i in my_list])
 
# List comprehension on Numpy array
print([i for i in my_array])
 
# Looping over list
for i in my_list:
    print(i)
 
# Looping over Numpy array
for i in my_array:
    print(i)
 
# Creating an iterator object from list:
iter_obj = iter(my_list)
 
# Access and print elements from the list:
print(next(iter_obj))

Conclusion

By following the steps outlined in this tutorial, you should now be able to read arrays in Python proficiently. Keep practicing these steps with different scenarios and arrays of your own to improve your understanding and become more comfortable with reading arrays in Python. Remember, practice is the key when it comes to mastering any programming language. Happy coding!