The following code produces an error in the diivision in python 3.5, 3.7 works in python 2.7

import math
import sys

x=int(1000112004278059472142857)
y1=int(1000003)
y2=int(1000033)
y3=int(1000037)
y4=int(1000039)
print (int(y1y2y3y4))
print (x)
#this product equals x Correct
print (int(y2y3*y4))
n=int(x / y1)
print (n)
#n is an incorrect answer
#works in pythoin 2.7
#Gives an incorrect answe in python 3.6.7, 3.7.1

I got:

NameError: name 'y1y2y3y4' is not defined.

@Jorge Teran
The division operator was changed in python 3. Now, if you use '/' for division between ints, the result would still be float. To get the same effect as python 2.x, you will have to use '//', i.e. floor division

Thanks

El dom., 6 de ene. de 2019 08:53, Yash Aggarwal <report@bugs.python.org>
escribió:

>
> Yash Aggarwal <aggarwal.yash2011@gmail.com> added the comment:
>
> @Jorge Teran
> The division operator was changed in python 3. Now, if you use '/' for
> division between ints, the result would still be float. To get the same
> effect as python 2.x, you will have to use '//', i.e. floor division
>
> ----------
> nosy: +FR4NKESTI3N
>
> _______________________________________
> Python tracker <report@bugs.python.org>
> <https://bugs.python.org/issue35672>
> _______________________________________
>

There is no need to call int() on a literal int: 1000003 is already an int, calling int() on it is just wasting time and making confusing code.

print (int(y1y2y3y4))

gives a NameError, since you don't have a variable "y1y2y3y4" defined. Please don't retype your example code from memory, make sure it works and then copy and paste code we can actually run.

I think we can simplify your example to this:

x = 1000112004278059472142857
y = 1000003
print(x/y)
print(int(x/y))


which correctly prints 

1.0001090039510477e+18
1000109003951047619

as the division operator uses floating point division in Python 3. Use the floor-division operator // to duplicate the Python 2 behaviour for ints.

Closing this as not a bug.

For reference, the OP reported the issue initially at https://github.com/python/psf-infra-meta/issues/17 (but it was closed because that's not the right tracker).

The y1y2y3y4 etc. are multiplications (mangled by not quoting the code in GitHub and then copy/paste from the rendered code).

nosy: + steven.daprano
messages: + msg333112

resolution: not a bug
stage: resolved