Is modifying the regular expression the most feasible solution?

[mimodbland]

Expected Behavior

It is expected that users whose name does not begin with a letter cannot be registered, and that letters, numbers, periods, underscores can then be used, completing a minimum number of characters that is channeled as an argument.

Actual Behavior

By modifying the regular expression that conditions the revision of the username parameter, we modify the behavior in block, satisfying the first condition, it cannot begin without a letter, and the second, we can use letters, numbers, period and underscore below with a minimum limit passed by parameter

Steps to Reproduce the Problem

Pass username as a parameter, following:

1 .blue.kale
2 _red_quinoa
3 ?othe>user

[Jedi-KnightCoder]

I added an if statement at the top the function that returned False if the first index of the string is Not a Letter.