How to pad with n characters in Python

With Python2.6 or better, there's no need to define your own function; the string format method can do all this for you:

In [18]: '{s:{c}^{n}}'.format(s='dog',n=5,c='x')
Out[18]: 'xdogx'

Using f-string: f'{"dog":x^5}'

yeah just use ljust or rjust to left-justify (pad right) and right-justify (pad left) with any given character.

For example ... to make '111' a 5 digit string padded with 'x'es

In Python3.6:

>>> '111'.ljust(5, 'x')
111xx

>>> '111'.rjust(5, 'x')
xx111