Python Exercise: Check a string represent an integer or not

Last update on March 26 2025 08:12:33 (UTC/GMT +8 hours)

35. String Represents Integer Checker

Write a Python program that checks whether a string represents an integer or not.

Pictorial Presentation:

Sample Solution:

Python Code:

# Request input from the user to input a string and assign it to the variable 'text'
text = input("Input a string: ")

# Remove leading and trailing whitespaces from the input string using the 'strip()' function
text = text.strip()

# Check if the length of the cleaned text is less than 1
if len(text) < 1:
    print("Input a valid text")  # If the text length is less than 1, display a message asking for valid input
else:
    # Check if all characters in the cleaned text are digits (0-9), indicating an integer
    if all(text[i] in "0123456789" for i in range(len(text))):
        print("The string is an integer.")  # If all characters are digits, display a message indicating an integer
    # Check if the text starts with a '+' or '-' and all subsequent characters are digits
    elif (text[0] in "+-") and all(text[i] in "0123456789" for i in range(1, len(text))):
        print("The string is an integer.")  # If the conditions for a signed integer are met, display an integer message
    else:
        print("The string is not an integer.")  # If none of the conditions are met, display a non-integer message 

Sample Output:

Input a string: python                                                                                        
The string is not an integer. 

Flowchart :

For more Practice: Solve these Related Problems:

• Write a Python program to check whether a given input string can be converted to an integer using exception handling.
• Write a Python program to validate if a string represents a valid integer using regular expressions.
• Write a Python program to determine if a string is an integer by checking if it consists solely of digits (with an optional leading sign).
• Write a Python program to implement a function that returns True if a string represents an integer and False otherwise.

Python Code Editor:

Have another way to solve this solution? Contribute your code (and comments) through Disqus.

Previous: Write a Python program to sum of two given integers. However, if the sum is between 15 to 20 it will return 20.
Next: Write a Python program to check a triangle is equilateral, isosceles or scalene.