Homework Assignment $1$: Username Validation

$**$Scenario:$**$ You are creating a registration form and need to validate the usernames.

$**$Task:$**$ Write a program that:

$*$ Asks the user to create a username.

$*$ Checks if the username starts with a capital letter.

$*$ Ensures it ends with a number.

$*$ Verify that it contains no special characters, except for underscores. Hint use replace$()$

$*$ Provides feedback for each requirement.

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# Example Output

Enter your desired username: User$\_123$

$-$ Starts with a capital letter: Yes

$-$ Ends with a number: Yes

$-$ Contains only allowed characters: Yes

Your username User$\_123$ is valid!