Define a function max() that takes two numbers as arguments and returns the largest of them.
Use the if-then-else construct available in Python. (It is true that Python has the max() function built in, but writing it yourself is nevertheless a good exercise.)
def new_max(a, b):
assert b != a, "Values are the same."
if a > b:
return a
elif b > a:
return b
print(new_max(46, 46.5))