Input processing/state machine function
Style

The style for naming in Python is as follows.


Variables should be in snake_case.
Constant variables should be in UPPER_SNAKE_CASE.
Functions should also be in snake_case.
Classes should be in PascalCase.


You should also replace comments in functions like this:

#keys = a list of all keybord keys currently being pressed.
#I have imported a module that has a bunch of variables that represent each key.
#keyup = the current key that was just released, if any.


To docstrings, like this:

"""Brief description of the function/class.

More detailed description of function/class.

Keyword Arguments:
argument -- Argument description.
...
"""




Design

There's not much about your design that I can nitpick, the only thing I'd really suggest is shortening these two blocks of code:

self.moveHorz('r')
self.accelerate('r')
self.set_crnt_acc('r')
self.faceDir = 'r'
self.des_dir = 'r'


And:

self.moveHorz('l')
self.accelerate('l')
self.set_crnt_acc('l')
self.faceDir = 'l'
self.des_dir = 'l'


To a shortened method, like this:

def change_direction(self, direction):
    if direction == "l" or direction == "r":
        self.moveHorz(direction)
        self.accelerate(direction)
        self.set_crnt_acc(direction)
        self.faceDir = direction
        self.des_dir = direction
    else:
        print("Direction must either be \"l\" or \"r\"")


This is especially useful if you need to repeat this code in many places.

On a side note, you should get rid of the magic values 'l' and 'r' and do something like this:

LEFT = 'l'
RIGHT = 'r'


You could also use integers to represent this as well:

LEFT = 0
RIGHT = 1


Or if you're feeling really adventurous, you can use an Enum, like this:

class Directions(Enum):
    LEFT = 0
    RIGHT = 1