Calculate Length of A String Without Using Python Library

Python is a versatile programming language known for its simplicity and readability. One common task in programming is to find the length of a string. While Python provides built-in functions len() to determine the length of a string, it’s also instructive to explore ways to achieve this without relying on library functions. In this article, we’ll discuss some different methods to calculate the length of a string using Python.

Calculate The Length Of A String Without Using Library Functions

Below, are the methods of Python programs to Calculate The Length Of A String Without Using Library Functions in Python.

• Length Of A String Using While Loop
• Iteration through Character using for loop

Length Of A String Using While Loop

In this example, in below code the Python function calculates the length of a string without using library functions by incrementing a counter until an `IndexError` is raised, indicating the end of the string.

Python3

def length_using_naive_counter(s):
    count = 0
    try:
        while True:
            s[count]
            count += 1
    except IndexError:
        pass
    return count

# Example Usage:
string_example = "Programming is exciting!"
result = length_using_naive_counter(string_example)
print(f"Length using naive counter: {result}")

Output

Length using naive counter: 24

Iteration through Character using for loop

In this example, Python function, `length_using_iteration`, calculates the length of a string by iteratively counting each character in the given string. The example usage demonstrates finding the length of the string “Hello, World!” using the iteration method.

Python3

def length_using_iteration(s):
    count = 0
    for char in s:
        count += 1
    return count

# Example Usage:
string_example = "Hello, World!"
result = length_using_iteration(string_example)
print(f"Length using iteration: {result}")

Output

Length using iteration: 13