为什么这个函数没有返回值？

Question

预先警告,我刚开始学习Python,这是我第一次在这个网站上学习.如果我的行为像n00b,请不要讨厌.

所以我创建了一个程序,它应该告诉你以光速和光速的因素来到达星(指定距离)需要多长时间.它从一个名为easygui的库开始,它创建了一个很好的窗口,用户可以选择一个因子.他们选择的因素成为变量"选择".这部分代码工作正常.理想情况下,该值将被输入到一个函数中,该函数将进行分解,并返回行程天数的值.这是不成功的.最有可能的是,我只是设置错了,所以如果有人知道使用函数的正确方法,我真的很感谢你的帮助!哦,我试着疯狂地评论,所以希望一切都有意义!

import easygui as eg                #the gui creation library I am using

dist  = 41000000000000          #distance to the star
light = 300000                  #speed of light


def Convert (factor):           #takes in factor chosen by user
    speed = light*factor        #the speed is the factor multiplied by the speed of light
    time = (dist/speed)/3600    # the time is the distance/divided by the speed, since thats a huge value in seconds, the /3600 should reduce it to days
    return time                 #"should" return the value it got for "time"


msg     = "Choose a warp factor:"                   #creates a gui  window for user to select factor
title   = "Warp Factor Selection"
choices = ["1", "3", "5", "10", "50", "100", "200", "500", "1000"]
choice   = eg.buttonbox(msg, title, choices)        #gui returns the user's selection as "choice" WORKS!

choice = float(choice)                                      #changes choice to float

if choice == 1:
    Convert(choice)                                         #attempts to feed  "choice" into the function "convert" DOES NOT WORK :(
    print (Convert(1))                                      #then print the value created from convert (have also tried print(time) but it always returns 0)

此时,故意将其设置为仅接受选择1作为因子.在我去之前做其他可能的因素之前,我想想出这个功能的东西

Answer 1

thefourtheye已经解释了原因,但是如果你想在将来避免这种情况,可以通过将它放在文件的顶部来切换到Python 3分区:

from __future__ import division

在Python 3中,它在类似于this(1/2 == .5)的情况下表现得更直观,而你仍然可以使用//(1//2 == 0)获得整数除法行为