Python: Check whether a given string has a capital letter, a lower case letter, a number and specified length using lambda

Last update on April 22 2025 12:52:00 (UTC/GMT +8 hours)

33. Password Checker Lambda

Write a Python program to check whether a given string contains a capital letter, a lower case letter, a number and a minimum length using lambda.

Sample Solution:

Python Code :

# Define a function 'check_string' that takes a string 'str1' as input
def check_string(str1):
    # Define a list 'messg' containing lambda functions with string validation conditions
    messg = [
        lambda str1: any(x.isupper() for x in str1) or 'String must have 1 upper case character.',
        lambda str1: any(x.islower() for x in str1) or 'String must have 1 lower case character.',
        lambda str1: any(x.isdigit() for x in str1) or 'String must have 1 number.',
        lambda str1: len(str1) >= 7 or 'String length should be at least 8.',
    ]
    
    # Generate a list 'result' by evaluating each lambda function in 'messg' for the input string 'str1'
    result = [x for x in [i(str1) for i in messg] if x != True]
    
    # Check if 'result' list is empty (all validation conditions are met)
    if not result:
        # If 'result' is empty, append 'Valid string.' indicating the string passes all validations
        result.append('Valid string.')
    
    # Return the 'result' list containing validation messages or 'Valid string.' if the string is valid
    return result    

# Get user input for a string 's'
s = input("Input the string: ")

# Print the result of string validation by calling the 'check_string' function with input 's'
print(check_string(s))

Sample Output:

Input the string:  W3resource
['Valid string.']

For more Practice: Solve these Related Problems:

Write a Python program to validate if a string contains at least one special character, one number, and both uppercase and lowercase letters using lambda.
Write a Python program to check if a string contains no whitespace, includes at least one digit, and at least one uppercase letter using lambda.
Write a Python program to verify if a string qualifies as a strong password (uppercase, lowercase, digit, special character, minimum length 8) using lambda.
Write a Python program to check if a string contains exactly two uppercase letters, three lowercase letters, and one digit using lambda.

Go to:

Previous: Write a Python program to count float number in a given mixed list using lambda.
Next: Write a Python program to filter the height and width of students, which are stored in a dictionary using lambda.

Python Code Editor:

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