Taking the floor of a float

Beware that taking the floor and casting to an int are not the same thing with negative numbers. If you really want the floor as an integer, you should cast to an int after calling math.floor().

>>> int(-0.5)
0
>>> math.floor(-0.5)
-1.0
>>> int(math.floor(-0.5))
-1

As long as your numbers are positive, you can simply convert to an int to round down to the next integer:

>>> int(3.1415)
3

For negative integers, this will round up, though.

The second approach is the way to go, but there's a way to shorten it.

from math import floor
floor(3.1415)

You can call int() on the float to cast to the lower int (not obviously the floor but more elegant)

int(3.745)  #3

Alternatively call int on the floor result.

from math import floor

f1 = 3.1415
f2 = 3.7415

print floor(f1)       # 3.0
print int(floor(f1))  # 3
print int(f1)         # 3
print int(f2)         # 3 (some people may expect 4 here)
print int(floor(f2))  # 3

http://docs.python.org/library/functions.html#int