In Python 2, floor()
returned a float value. Although not obvious to me, I found a few explanations clarifying why it may be useful to have floor()
floor()
rounds down. int()
truncates. The difference is clear when you use negative numbers:
>>> import math
>>> math.floor(-3.5)
-4
>>> int(-3.5)
-3
Rounding down on negative numbers means that they move away from 0, truncating moves them closer to 0.
Putting it differently, the floor()
is always going to be lower or equal to the original. int()
is going to be closer to zero or equal.
I test time complexity of both method they are the same
from time import time
import math
import random
r = 10000000
def floorTimeFunction():
for i in range(r):
math.floor(random.randint(-100,100))
def intTimeFunction():
for i in range(r):
int(random.randint(-100,100))
t0 = time()
floorTimeFunction()
t1 = time()
intTimeFunction()
t2 = time()
print('function floor takes %f' %(t1-t0))
print('function int takes %f' %(t2-t1))
output is:
# function floor takes 11.841985
# function int takes 11.841325