Changed parameter input in Initial Solution to program_input.

No, input is definitely a reserved keyword. It's just that python does not raise any error if you want to override the value, but that's still a very bad habit.

$ python 
Python 2.7.13 (default, Jan 12 2017, 17:59:37) 
[GCC 6.3.1 20161221 (Red Hat 6.3.1-1)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> input
<built-in function input>
>>> input = 10
>>> input
10

$ python2
Python 2.7.12 (v2.7.12:d33e0cf91556, Jun 26 2016, 12:10:39) 
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> input = 10
>>> ^D
$ python3
Python 3.5.2 (v3.5.2:4def2a2901a5, Jun 26 2016, 10:47:25) 
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> input = 10
>>> ^D

Afaik input is no longer a reserved keyword in python
it may have been when you commented though.

typical kata solution in python, nice one

Nice kata, pretty simple and pretty hard.
But 'input' is reserved word in Python, it'd be nice to change it.

Yep, this problem is still here. First two lines of tests should be replaced to:
bin = Alphabet['BINARY']; oct = Alphabet['OCTAL']; dec = Alphabet['DECIMAL']; hex = Alphabet['HEXA_DECIMAL'];
allow = Alphabet['ALPHA_LOWER']; alup = Alphabet['ALPHA_UPPER']; alpha = Alphabet['ALPHA']; alnum = Alphabet['ALPHA_NUMERIC'];