>>> numerator = 29
>>> denom = 1009
>>> print str(float(numerator/denom))
0.0
I just want it to return a decimal...
views:
247answers:
4
+8
A:
Until version 3, Python's division operator, /, behaved like C's division operator when presented with two integer arguments: it returns an integer result that's truncated down when there would be a fractional part. See: PEP 238
>>> n = 29
>>> d = 1009
>>> print str(float(n)/d)
0.0287413280476
In python 2 (and maybe earlier) you could use:
>>> from __future__ import division
>>> n/d
0.028741328047571853
The MYYN
2009-11-24 01:34:10
+3
A:
In Python 2.x, division works like it does in C-like languages: if both arguments are integers, the result is truncated to an integer, so 29/1009 is 0. 0 as a float is 0.0. To fix it, cast to a float before dividing:
print str(float(numerator)/denominator)
In Python 3.x, the division acts more naturally, so you'll get the correct mathematical result (within floating-point error).
Adam Rosenfield
2009-11-24 01:35:49
It's sufficient to cast either of the operands to float(). I generally recommend casting the numerator as it locates the cast at the beginning of the expression where readers will normally see it more readily.
Jim Dennis
2009-11-24 05:55:55
Yes it is, but this seemed more "proper" to me just because it was more transparent in its casting. But yes, casting one alone is enough.
inspectorG4dget
2009-11-24 06:59:17
A:
In your evaluation you are casting the result, you need to instead cast the operands.
Recursion
2009-11-24 02:22:30