Python division

Question

I was trying to normalize a set of numbers from -100 to 0 to a range of 10-100 and was having problems only to notice that even with no variables at all, this does not evalu

Answer 1

It has to do with the version of python that you use. Basically it adopts the C behavior: if you divide two integers, the results will be rounded down to an integer. Also keep in mind that Python does the operations from left to right, which plays a role when you typecast.

Example: Since this is a question that always pops in my head when I am doing arithmetic operations (should I convert to float and which number), an example from that aspect is presented:

>>> a = 1/2/3/4/5/4/3
>>> a
0

When we divide integers, not surprisingly it gets lower rounded.

>>> a = 1/2/3/4/5/4/float(3)
>>> a
0.0

If we typecast the last integer to float, we will still get zero, since by the time our number gets divided by the float has already become 0 because of the integer division.

>>> a = 1/2/3/float(4)/5/4/3
>>> a
0.0

Same scenario as above but shifting the float typecast a little closer to the left side.

>>> a = float(1)/2/3/4/5/4/3
>>> a
0.0006944444444444445

Finally, when we typecast the first integer to float, the result is the desired one, since beginning from the first division, i.e. the leftmost one, we use floats.

Extra 1: If you are trying to answer that to improve arithmetic evaluation, you should check this

Extra 2: Please be careful of the following scenario:

>>> a = float(1/2/3/4/5/4/3)
>>> a
0.0