Python Program to Calculate length of a String

1. Python program to calculate length of a String without using len() function

First we will see how to find the length of string without using library function len(). Here we are taking the input from user and counting the number of characters in the input string using for loop.

# User inputs the string and it gets stored in variable str
str = input("Enter a string: ")

# counter variable to count the character in a string
counter = 0
for s in str:
      counter = counter+1
print("Length of the input string is:", counter)

Output:

Enter a string: noidatut
Length of the input string is: 8

2. Program to find the length of string using library function

In the above program we have not used the library function to find length, however we can do the same thing by using a built-in function. The function len() returns the length of a given string. Lets have a look at the following code:

# User inputs the string and it gets stored in variable str
str = input("Enter a string: ")

# using len() function to find length of str
print("Length of the input string is:", len(str))

Output

Enter a string: noidatut
Length of the input string is: 8