Python Executables Running on Earlier Versions

Question

Lets say Person 1 has a python executable file (mac) that was written in Python 3.x. Person 1 sends said file to Person 2, who also has a mac, but only has Python 2.6.1. When Person 2 runs that file, will it work?

Someone said they needed to see the code, so:

#!/usr/bin/env python
# -*- coding: UTF8 -*-
topo1 = 0
topo2 = 0
print("This program helps compare two players: ")
print("It only uses that player's stats from the previous two years to determine their worth in fantasy baseball")
def complay1():
    global topo1
    print("Enter in the first player's stats below")
    homerun = input("Enter in the player's home run total from the most recent year: ")
    sb = input("Enter in the player's stolen base total from the most recent year: ")
    hit = input("Enter in the player's hit total from the most recent year: ")
    walks = input("Enter in the player's walk total from the most recent year: ")
    doubles = input("Enter in the player's doubles total from the most recent year: ")
    rbi = input("Enter in the player's RBI total from the most recent year: ")
    ba = input("Enter in the player's batting average from the most recent year, do not include a decimal point: ")
    hitL = input("Enter in the player's hit total from the year before the most recent year: ")
    homerunL = input("Enter in the player's home run total from the year before the most recent year: ")
    age = input("Enter in the player's age: ")
    gp = input("How many games did the player play last year?: ")
    topo1 += int(homerun)*3
    topo1 += int(sb)*2
    topo1 += int(hit)/2.5
    topo1 += int(walks)/4
    topo1 += int(doubles)
    topo1 += int(rbi)/3
    topo1 += int(hitL)/15
    topo1 += int(homerunL)
    topo1/(int(gp)/4)
    topo1 -= int(age)
    topo1 += int(ba)/2
    print(topo1, "is the total PLV+ for this player")
def complay2():
    global topo2
    print("Enter in the second player's stats below")
    homerun = input("Enter in the player's home run total from the most recent year: ")
    sb = input("Enter in the player's stolen base total from the most recent year: ")
    hit = input("Enter in the player's hit total from the most recent year: ")
    walks = input("Enter in the player's walk total from the most recent year: ")
    doubles = input("Enter in the player's doubles total from the most recent year: ")
    rbi = input("Enter in the player's RBI total from the most recent year: ")
    ba = input("Enter in the player's batting average from the most recent year, do not include a decimal point: ")
    hitL = input("Enter in the player's hit total from the year before the most recent year: ")
    homerunL = input("Enter in the player's home run total from the year before the most recent year: ")
    age = input("Enter in the player's age: ")
    gp = input("How many games did the player play last year?: ")
    topo2 += int(homerun)*3
    topo2 += int(sb)*2
    topo2 += int(hit)/2.5
    topo2 += int(walks)/4
    topo2 += int(doubles)
    topo2 += int(ba)/2
    topo2 += int(rbi)/3
    topo2 += int(hitL)/15
    topo2 += int(homerunL)
    topo2/(int(gp)/4)
    topo2 -= int(age)
    topo1 += int(ba)/2
    print(topo2, "is the total PLV+ for this player")       
complay1()    
complay2()
if topo1 > topo2:
    print("Player 1 is", ((topo1/topo2)*100)-100, "percent better")
if topo2 > topo1:
    print("Player 2 is", ((topo2/topo1)*100)-100, "percent better")

Answer 1

Probably not, the major version changes have no backward compatiblity.

EDIT: For your code example, it probably works. The only thing changed between 2 and 3 in your script is that print isn't a function in Python 2, which is unimportant because print(x) is the same as print x for the Python 2 interpreter, extra brackets don't hurt.

EDIT2: The division will break too, as said in a different answer. This is because int/int will result in an int in Python 2 and in an float in Python 3. This means 5 / 2 is 2 in Python 2 and 2.5 in Python 3. from __future__ import division fixes this.