Assuming a, b are integers, the following answers are exact:
def div_floor(a, b):
return a // b
def div_ceil(a, b):
return (a + b - 1) // b
def div_trunc(a, b):
return a // b if (a < 0) == (b < 0) else -(-a // b)
def div_round(a, b):
return (2*a + b) // (2*b)