>>> def FncX(X):
... return eval('Fnc'+X)
...
>>> FncX('X')
<function FncX at 0x0093DDF0>
>>> FncX('X')()
Traceback (most recent call last):
File "<stdin>", line 1, in ?
TypeError: FncX() takes exactly 1 argument (0 given)
>>>

エレガントすぎて涙が出ますね