Converting Strings to Integers in Python

Learn how to convert strings to integers in Python with this comprehensive tutorial. Understand the relationship between strings and integers, and gain practical experience with code snippets. …

Learn how to convert strings to integers in Python with this comprehensive tutorial. Understand the relationship between strings and integers, and gain practical experience with code snippets.

Definition of the Concept

In programming, a string is a sequence of characters, like a word or a phrase, enclosed in quotes (" " or ' '). An integer, on the other hand, is a whole number without any fractional part. Converting a string to an integer involves changing the string representation of a number into its actual numerical value.

Step-by-Step Explanation

To convert a string to an integer in Python, follow these steps:

1. Understand the String Representation: Familiarize yourself with how numbers are represented as strings in Python. For example, the string "123" represents the integer 123.
2. Use the Built-in int() Function: Utilize Python’s built-in int() function to convert a string to an integer. This function takes one argument: the string you want to convert.

Simple Code Snippets

Here are some code snippets that demonstrate how to convert strings to integers in Python:

Example 1: Converting a simple string

# Define a string containing a number
num_str = "123"

# Convert the string to an integer using int()
num_int = int(num_str)

print(num_int)  # Output: 123

Example 2: Handling invalid inputs

# Define a string containing a non-numeric value
non_num_str = "hello"

try:
    num_int = int(non_num_str)
except ValueError as e:
    print(e)  # Output: invalid literal for int() with base 10: 'hello'

Example 3: Converting strings in a list

# Define a list of string representations of numbers
num_list = ["123", "456", "789"]

# Use a list comprehension to convert the strings to integers
int_list = [int(num) for num in num_list]

print(int_list)  # Output: [123, 456, 789]

Code Explanation

• The int() function converts its argument to an integer. If the input is not a valid integer representation (e.g., "hello"), it raises a ValueError.
• In Example 2, we catch the ValueError exception raised by int(non_num_str) and print the error message.
• In Example 3, we use a list comprehension to apply the int() function to each string in the input list.

Readability

This article aims for a Fleisch-Kincaid readability score of 8-10, making it accessible to beginners while still conveying complex information. The language used is straightforward and easy to understand, avoiding jargon whenever possible.