Python Array Exercises – Practice Problems with Solutions

Python arrays are used to store multiple values of the same type in a single variable. While Python lists are more commonly used, the array module from Python’s standard library offers memory-efficient storage and is ideal for numeric data.

In this article, you’ll find hands-on exercises, solutions, and explanations to help solidify your understanding of arrays in Python.

Introduction to Python Arrays

To use arrays in Python, import the array module:

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

'i' is the type code for signed integers. Other codes include 'f' for float, 'd' for double, etc.

Exercise 1: Create and Traverse an Array

Task:

• Create an array of 5 integers.
• Traverse it and print each element.

import array

arr = array.array('i', [10, 20, 30, 40, 50])

for num in arr:
    print(num)

Exercise 2: Append, Insert, and Extend Arrays

Task:

• Append a number to the array.
• Insert a value at position 2.
• Extend the array with another list.

arr.append(60)
arr.insert(2, 25)
arr.extend([70, 80])
print(arr)  # array('i', [10, 20, 25, 30, 40, 50, 60, 70, 80])

Exercise 3: Remove and Pop Elements

Task:

• Remove value 25.
• Pop the last item.
• Try to remove an item that doesn’t exist and handle the error.

arr.remove(25)     # Removes the first occurrence of 25
arr.pop()          # Removes the last element

try:
    arr.remove(999)
except ValueError:
    print("Element not found!")

Exercise 4: Search for Elements

Task:

• Search for the index of element 30.
• Check if 100 is present.

index = arr.index(30)
print("Index of 30:", index)

if 100 in arr:
    print("100 found")
else:
    print("100 not found")

Exercise 5: Looping and Indexing

Task:

• Loop through array using for and while with index.
• Print the value and index.

for i in range(len(arr)):
    print(f"Index {i} = {arr[i]}")

# Using while loop
i = 0
while i < len(arr):
    print(f"While Index {i} = {arr[i]}")
    i += 1

Exercise 6: Reverse and Slice Arrays

Task:

• Reverse the array using slicing.
• Slice from index 2 to 5.

reversed_arr = arr[::-1]
print("Reversed:", reversed_arr)

slice_arr = arr[2:6]
print("Slice 2 to 5:", slice_arr)

Exercise 7: Array Length and Buffer Info

Task:

• Find the length of the array.
• Get memory buffer info.

print("Length:", len(arr))
print("Buffer Info:", arr.buffer_info())

buffer_info() returns a tuple (memory_address, number_of_elements)

Practice Quiz

Question 1:

What will the following code output?

import array
arr = array.array('i', [1, 2, 3, 4])
arr.insert(1, 100)
print(arr[1])

Answer: 100

Question 2:

Which method is used to add multiple elements?

• A. insert()
• B. append()
• C. extend()
• D. pop()

Answer: C. extend()

Summary

• Python arrays using the array module are efficient for numeric data.
• Basic operations include creation, traversal, insertion, removal, searching, and slicing.
• These exercises help reinforce foundational array handling before diving into advanced data structures like NumPy arrays or lists of objects.

FAQs

Q1. What’s the difference between array and list in Python?
Arrays store same-type elements (efficient for large numeric data), while lists can store mixed types.

Q2. Can I store strings in an array?
Not with the array module. For strings, use lists or specialized libraries like NumPy.

Q3. What are valid type codes for arrays?
Examples: 'i' (int), 'f' (float), 'd' (double), 'b' (signed char)

Q4. Can arrays be multidimensional in Python?
Not with array module. Use NumPy for multi-dimensional arrays.