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

Last update on June 12 2025 12:41:33 (UTC/GMT +8 hours)

Check string for capital, lower, number, length.

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

Sample Solution:

Python Code:

# Define a function to check the validity of a string based on certain criteria
def check_string(s):
    # Initialize an empty list to store error messages
    messg = []

    # Check if the string contains at least one uppercase character
    if not any(x.isupper() for x in s):
        messg.append('String must have 1 upper case character.')

    # Check if the string contains at least one lowercase character
    if not any(x.islower() for x in s):
        messg.append('String must have 1 lower case character.')

    # Check if the string contains at least one digit
    if not any(x.isdigit() for x in s):
        messg.append('String must have 1 number.')

    # Check if the string length is at least 8 characters
    if len(s) < 8:
        messg.append('String length should be at least 8.')

    # If there are no error messages, add a message indicating the string is valid
    if not messg:
        messg.append('Valid string.')

    # Return the list of error messages or the validation message
    return messg

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

# Call the function to check the string and print the result
print(check_string(s))

Sample Output:

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

Flowchart:

Flowchart: Check whether a given string has a capital letter, a lower case letter, a number and specified length.

For more Practice: Solve these Related Problems:

Write a Python program to validate that an input string contains at least one uppercase letter, one lowercase letter, one digit, and meets a minimum length requirement.
Write a Python program to use regular expressions to verify that a string satisfies conditions for capital letters, lowercase letters, numbers, and length.
Write a Python program to implement a function that returns a list of missing criteria if an input string fails to meet specified requirements.
Write a Python program to prompt the user for a string and print "Valid string." only if all character type conditions are met.

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