Truncate to three decimals in Python

Question

How do I get 1324343032.324?

As you can see below, the following do not work:

>>1324343032.324325235 * 1000 / 1000
1324343032.3243253
>>i         


        

Answer 1

Use the decimal module. But if you must use floats and still somehow coerce them into a given number of decimal points converting to string an back provides a (rather clumsy, I'm afraid) method of doing it.

>>> q = 1324343032.324325235 * 1000 / 1000
>>> a = "%.3f" % q
>>> a
'1324343032.324'
>>> b = float(a)
>>> b
1324343032.324

So:

float("%3.f" % q)