This little Python program converts numbers from different numerative systems (hexadecimal, decimal, binary)

usage: numconverter.py [-h] [-H HEX] [-b BINARY] [-d DECIMAL] [-v]

Covert hexadecimal, decimal and binary numbers. Use only one argument at a time.

optional arguments:
-h, --help                      show this help message and exit
-H HEX, --hex HEX               hexadecimal number to convert
-b BINARY, --binary BINARY      binary number to convert
-d DECIMAL, --decimal DECIMAL   positive decimal number to convert
-v, --verbose

(I know, Python brings its own methods to do this, but I needed some more output and I wanted to refresh my knowledge, doing this maths and Python programming.)