Temp Converter with Kelvin

[ichabod801]

Also, look at your input checking section. Note that this is a much easier way to do it:

badInput = True
while badInput:
    which = input('Enter selection: ')
    if which in ['F', 'C', 'K']:
        badInput = False

That reduces three conditions to one condition. But then, if you just have one condition, you can stick that condition in the while statement:

which = 'X'
while which not in ['F', 'C', 'K']:
    which = input('Enter selection: ')