String validation checks in Python - Mini Project: Build & Apply

String validation checks

📖 Scenario: You are building a simple program to check different properties of a user's input text. This helps in many real-life cases like validating passwords, usernames, or form inputs.

🎯 Goal: Build a program that checks if a given string contains only letters, only digits, or is alphanumeric, and then prints the results.

📋 What You'll Learn

Create a variable with a specific string value

Create a variable to store a check result

Use string methods to check if the string is alphabetic, numeric, or alphanumeric

Print the results clearly

💡 Why This Matters

🌍 Real World

String validation is used in forms, passwords, and user input to ensure data is correct and safe.

💼 Career

Many programming jobs require validating user input to prevent errors and security issues.

1

Create the input string

Create a variable called user_input and set it to the string "Hello123".

Python

# Create the variable user_input with the value "Hello123"
# Your code here

Need a hint?

Use the equals sign = to assign the string to the variable.

2

Create variables for validation results

Create three variables called is_alpha, is_digit, and is_alnum. Set each one to False initially.

Python

user_input = "Hello123"
# Create variables is_alpha, is_digit, and is_alnum and set them to False
# Your code here

Need a hint?

Each variable should be set to the boolean value False.

3

Check string properties using string methods

Set is_alpha to user_input.isalpha(), is_digit to user_input.isdigit(), and is_alnum to user_input.isalnum().

Python

user_input = "Hello123"
is_alpha = False
is_digit = False
is_alnum = False
# Use string methods to update is_alpha, is_digit, and is_alnum
# Your code here

Need a hint?

Use the string methods isalpha(), isdigit(), and isalnum() on user_input.

4

Print the validation results

Print the values of is_alpha, is_digit, and is_alnum each on a new line with labels exactly as shown: "Is alphabetic: ", "Is digit: ", and "Is alphanumeric: ".

Python

user_input = "Hello123"
is_alpha = user_input.isalpha()
is_digit = user_input.isdigit()
is_alnum = user_input.isalnum()
# Print the results with labels
# Your code here

Need a hint?

Use three print() statements with the exact labels and variables.