/ behavior differs in 2.X and 3.X.
If your programs depend on truncating integer division, use // in both 2.X and 3.X.
If your programs require floating-point results with remainders for integers, use float to guarantee that one operand is a float around a / when run in 2.X:
X = Y // Z # Always truncates, always an int result for ints in 2.X and 3.X X = Y / float(Z) # Guarantees float division with remainder in either 2.X or 3.X
Or you can enable 3.X / division in 2.X with a __future__ import, rather than forcing it with float conversions:
C:\Python27\python >>> from __future__ import division # Enable 3.X "/" behavior >>> 10 / 4 2.5 >>> 10 // 4 # Integer // is the same in both 2
It must appear as the first executable line when used in a script file.