我怎样才能让一个进程始终在 python 的后台运行？
How can I have a process always running in background in python?
所以我主要使用 tkinter 在 python 中制作了一个非常简单的游戏。游戏是这样的：你是一张纸，铅笔从四个主要方向（左上和右上）射出。你需要避开铅笔，当你被击中时，你 "die" 游戏就结束了。所以在 mainloop() 中，我将纸张绑定到箭头键上。我需要能够从背景的 4 个侧面射出铅笔。当主循环发生时，函数 pencilAttack() 需要持续运行。我正在使用 Python 2.7.5 并愿意使用（并且可能必须使用）multithreading/processing。这是我所有的代码，它几乎可以工作，但不完全是。如果您有任何问题，请随时提出。感谢您的帮助！
import Tkinter
import tkMessageBox
from Tkinter import *
import random
import time
def key(event): #"IB" stands for in bounds, "OOB" stands for out of bounds
right="IB"; left="IB"; top="IB"; bottom="IB"
cntr1=0; cntr2=0; cntr3=0; cntr4=0
while cntr1<len(C.find_overlapping(760,41,760,559)):
if C.find_overlapping(760,41,760,559)[cntr1]==17:
right="OOB"
break
cntr1+=1
while cntr2<len(C.find_overlapping(40,41,40,559)):
if C.find_overlapping(40,41,40,559)[cntr2]==17:
left="OOB"
break
cntr2+=1
while cntr3<len(C.find_overlapping(41,40,759,40)):
if C.find_overlapping(41,40,759,40)[cntr3]==17:
top="OOB"
break
cntr3+=1
while cntr4<len(C.find_overlapping(41,560,759,560)):
if C.find_overlapping(41,560,759,560)[cntr4]==17:
bottom="OOB"
break
cntr4+=1
if (event.keysym == 'Right') and (right!="OOB"):
C.move(paper, 20, 0)
if (event.keysym == 'Left') and (left!="OOB"):
C.move(paper, -20, 0)
if (event.keysym == 'Up') and (top!="OOB"):
C.move(paper, 0, -20)
if (event.keysym == 'Down') and (bottom!="OOB"):
C.move(paper, 0, 20)
def ifDead():
cntr5=0
bbox=C.bbox(17)
while cntr5<len(C.find_overlapping(*bbox)):
if C.find_overlapping(*bbox)[cntr5]>=18 and C.find_overlapping(*bbox)[cntr5]<=65:
return True
cntr5+=1
def pencilAttack():
currentPencil=random.choice(allPencils)
print currentPencil
print type(currentPencil)
cntr=0
dead=False
if currentPencil>=18 and currentPencil<=27:
C.move(currentPencil, 70, 0)
time.sleep(.5)
while cntr<200:
print cntr
C.move(currentPencil, 5, 0)
if ifDead()==True:
dead=True
break
cntr+=1
C.move(currentPencil, -1070, 0)
if currentPencil>=28 and currentPencil<=41:
C.move(currentPencil, -70, 0)
time.sleep(.5)
while cntr<200:
print cntr
C.move(currentPencil, -5, 0)
if ifDead()==True:
dead=True
break
cntr+=1
C.move(currentPencil, 1070, 0)
if currentPencil>=42 and currentPencil<=51:
C.move(currentPencil, 0, 70)
time.sleep(.5)
while cntr<200:
print cntr
C.move(currentPencil, 0, 5)
if ifDead()==True:
dead=True
break
cntr+=1
C.move(currentPencil, 0, -1070)
if currentPencil>=52 and currentPencil<=65:
C.move(currentPencil, 0, -70)
time.sleep(.5)
while cntr<200:
print cntr
C.move(currentPencil, 0, -5)
if ifDead()==True:
dead=True
break
cntr+=1
C.move(currentPencil, 0, 1070)
if dead:
top.destroy()
top = Tkinter.Tk()
C = Tkinter.Canvas(top, bg="light goldenrod", height=600, width=800)
#this below creates the background
C.create_line(760,41,760,559, fill="green")#light goldenrod
C.create_line(40,41,40,559, fill="blue")
C.create_line(41,40,759,40, fill="black")
C.create_line(41,560,759,560, fill="red")
C.create_line(0,100,1000,100, fill="deep sky blue")
C.create_line(0,150,1000,150, fill="deep sky blue")
C.create_line(0,200,1000,200, fill="deep sky blue")
C.create_line(0,250,1000,250, fill="deep sky blue")
C.create_line(0,300,1000,300, fill="deep sky blue")
C.create_line(0,350,1000,350, fill="deep sky blue")
C.create_line(0,400,1000,400, fill="deep sky blue")
C.create_line(0,450,1000,450, fill="deep sky blue")
C.create_line(0,500,1000,500, fill="deep sky blue")
C.create_line(0,550,1000,550, fill="deep sky blue")
C.create_line(0,600,1000,600, fill="deep sky blue")
C.create_line(75,0,75,1000, fill="red")
#this below creates the photos
rPencil = PhotoImage(file="H:\Computer Programming\Pencil right.gif")
lPencil = PhotoImage(file="H:\Computer Programming\Pencil left.gif")
tPencil = PhotoImage(file="H:\Computer Programming\Pencil top.gif")
bPencil = PhotoImage(file="H:\Computer Programming\Pencil bottom.gif")
paperpic = PhotoImage(file="H:\Computer Programming\paper2.gif")
paper = C.create_image(400,400, image = paperpic)
allPencils=[]
#ignore the one right under this
#lPencils-> -30x rPencils-> 830x tPencil-> -30y bPencil-> 630y
#all these below create the pencils out of bounds to later be moved into place
pencil1=C.create_image(-100, 66, image = lPencil, tags="Lpencil");allPencils.append(pencil1)
pencil2=C.create_image(-100, 118, image = lPencil, tags="Lpencil");allPencils.append(pencil2)
pencil3=C.create_image(-100, 170, image = lPencil, tags="Lpencil");allPencils.append(pencil3)
pencil4=C.create_image(-100, 222, image = lPencil, tags="Lpencil");allPencils.append(pencil4)
pencil5=C.create_image(-100, 274, image = lPencil, tags="Lpencil");allPencils.append(pencil5)
pencil6=C.create_image(-100, 326, image = lPencil, tags="Lpencil");allPencils.append(pencil6)
pencil7=C.create_image(-100, 378, image = lPencil, tags="Lpencil");allPencils.append(pencil7)
pencil8=C.create_image(-100, 430, image = lPencil, tags="Lpencil");allPencils.append(pencil8)
pencil9=C.create_image(-100, 482, image = lPencil, tags="Lpencil");allPencils.append(pencil9)
pencil10=C.create_image(-100, 534, image = lPencil, tags="Lpencil");allPencils.append(pencil10)
pencil11=C.create_image(900, 534, image = rPencil, tags="Rpencil");allPencils.append(pencil11)
pencil12=C.create_image(900, 482, image = rPencil, tags="Rpencil");allPencils.append(pencil12)
pencil13=C.create_image(900, 430, image = rPencil, tags="Rpencil");allPencils.append(pencil13)
pencil14=C.create_image(900, 378, image = rPencil, tags="Rpencil");allPencils.append(pencil14)
pencil15=C.create_image(900, 326, image = rPencil, tags="Rpencil");allPencils.append(pencil15)
pencil16=C.create_image(900, 274, image = rPencil, tags="Rpencil");allPencils.append(pencil16)
pencil17=C.create_image(900, 222, image = rPencil, tags="Rpencil");allPencils.append(pencil17)
pencil18=C.create_image(900, 170, image = rPencil, tags="Rpencil");allPencils.append(pencil18)
pencil19=C.create_image(900, 118, image = rPencil, tags="Rpencil");allPencils.append(pencil19)
pencil20=C.create_image(900, 66, image = rPencil, tags="Rpencil");allPencils.append(pencil20)
pencil21=C.create_image(66, -100, image = tPencil, tags="Tpencil");allPencils.append(pencil21)
pencil22=C.create_image(118, -100, image = tPencil, tags="Tpencil");allPencils.append(pencil22)
pencil23=C.create_image(170, -100, image = tPencil, tags="Tpencil");allPencils.append(pencil23)
pencil24=C.create_image(222, -100, image = tPencil, tags="Tpencil");allPencils.append(pencil24)
pencil25=C.create_image(274, -100, image = tPencil, tags="Tpencil");allPencils.append(pencil25)
pencil26=C.create_image(326, -100, image = tPencil, tags="Tpencil");allPencils.append(pencil26)
pencil27=C.create_image(378, -100, image = tPencil, tags="Tpencil");allPencils.append(pencil27)
pencil28=C.create_image(430, -100, image = tPencil, tags="Tpencil");allPencils.append(pencil28)
pencil29=C.create_image(482, -100, image = tPencil, tags="Tpencil");allPencils.append(pencil29)
pencil30=C.create_image(534, -100, image = tPencil, tags="Tpencil");allPencils.append(pencil30)
pencil31=C.create_image(586, -100, image = tPencil, tags="Tpencil");allPencils.append(pencil31)
pencil32=C.create_image(638, -100, image = tPencil, tags="Tpencil");allPencils.append(pencil32)
pencil33=C.create_image(690, -100, image = tPencil, tags="Tpencil");allPencils.append(pencil33)
pencil34=C.create_image(742, -100, image = tPencil, tags="Tpencil");allPencils.append(pencil34)
pencil35=C.create_image(66, 700, image = bPencil, tags="Bpencil");allPencils.append(pencil35)
pencil36=C.create_image(118, 700, image = bPencil, tags="Bpencil");allPencils.append(pencil36)
pencil37=C.create_image(170, 700, image = bPencil, tags="Bpencil");allPencils.append(pencil37)
pencil38=C.create_image(222, 700, image = bPencil, tags="Bpencil");allPencils.append(pencil38)
pencil39=C.create_image(274, 700, image = bPencil, tags="Bpencil");allPencils.append(pencil39)
pencil40=C.create_image(326, 700, image = bPencil, tags="Bpencil");allPencils.append(pencil40)
pencil41=C.create_image(378, 700, image = bPencil, tags="Bpencil");allPencils.append(pencil41)
pencil42=C.create_image(430, 700, image = bPencil, tags="Bpencil");allPencils.append(pencil42)
pencil43=C.create_image(482, 700, image = bPencil, tags="Bpencil");allPencils.append(pencil43)
pencil44=C.create_image(534, 700, image = bPencil, tags="Bpencil");allPencils.append(pencil44)
pencil45=C.create_image(586, 700, image = bPencil, tags="Bpencil");allPencils.append(pencil45)
pencil46=C.create_image(638, 700, image = bPencil, tags="Bpencil");allPencils.append(pencil46)
pencil47=C.create_image(690, 700, image = bPencil, tags="Bpencil");allPencils.append(pencil47)
pencil48=C.create_image(742, 700, image = bPencil, tags="Bpencil");allPencils.append(pencil48)
C.pack()
top.bind_all('<Key>', key)
top.after(1000,pencilAttack)
top.mainloop()
你不应该为此使用线程。在几乎所有 GUI 框架中，都有一个 "event loop" 线程分派用户输入事件并更新 UI。如果您尝试从不同的线程更新 UI，将不会有任何好事发生。如果你幸运的话，框架会抓住你并抛出一个错误告诉你不要这样做，否则你最终会遇到难以调试的竞争条件。
我建议您立即执行操作，然后使用 top.after(500, pencilAttack).
顺便说一句，在 gui 程序中使用线程的唯一原因是在后台执行繁重的阻塞工作，例如从网络加载资源或进行某种 CPU 密集计算。在这种情况下，您的 GUI 框架将提供用于将函数调用从后台线程发布到应用程序线程的方法。
所以我主要使用 tkinter 在 python 中制作了一个非常简单的游戏。游戏是这样的：你是一张纸，铅笔从四个主要方向（左上和右上）射出。你需要避开铅笔，当你被击中时，你 "die" 游戏就结束了。所以在 mainloop() 中，我将纸张绑定到箭头键上。我需要能够从背景的 4 个侧面射出铅笔。当主循环发生时，函数 pencilAttack() 需要持续运行。我正在使用 Python 2.7.5 并愿意使用（并且可能必须使用）multithreading/processing。这是我所有的代码，它几乎可以工作，但不完全是。如果您有任何问题，请随时提出。感谢您的帮助！
import Tkinter
import tkMessageBox
from Tkinter import *
import random
import time
def key(event): #"IB" stands for in bounds, "OOB" stands for out of bounds
right="IB"; left="IB"; top="IB"; bottom="IB"
cntr1=0; cntr2=0; cntr3=0; cntr4=0
while cntr1<len(C.find_overlapping(760,41,760,559)):
if C.find_overlapping(760,41,760,559)[cntr1]==17:
right="OOB"
break
cntr1+=1
while cntr2<len(C.find_overlapping(40,41,40,559)):
if C.find_overlapping(40,41,40,559)[cntr2]==17:
left="OOB"
break
cntr2+=1
while cntr3<len(C.find_overlapping(41,40,759,40)):
if C.find_overlapping(41,40,759,40)[cntr3]==17:
top="OOB"
break
cntr3+=1
while cntr4<len(C.find_overlapping(41,560,759,560)):
if C.find_overlapping(41,560,759,560)[cntr4]==17:
bottom="OOB"
break
cntr4+=1
if (event.keysym == 'Right') and (right!="OOB"):
C.move(paper, 20, 0)
if (event.keysym == 'Left') and (left!="OOB"):
C.move(paper, -20, 0)
if (event.keysym == 'Up') and (top!="OOB"):
C.move(paper, 0, -20)
if (event.keysym == 'Down') and (bottom!="OOB"):
C.move(paper, 0, 20)
def ifDead():
cntr5=0
bbox=C.bbox(17)
while cntr5<len(C.find_overlapping(*bbox)):
if C.find_overlapping(*bbox)[cntr5]>=18 and C.find_overlapping(*bbox)[cntr5]<=65:
return True
cntr5+=1
def pencilAttack():
currentPencil=random.choice(allPencils)
print currentPencil
print type(currentPencil)
cntr=0
dead=False
if currentPencil>=18 and currentPencil<=27:
C.move(currentPencil, 70, 0)
time.sleep(.5)
while cntr<200:
print cntr
C.move(currentPencil, 5, 0)
if ifDead()==True:
dead=True
break
cntr+=1
C.move(currentPencil, -1070, 0)
if currentPencil>=28 and currentPencil<=41:
C.move(currentPencil, -70, 0)
time.sleep(.5)
while cntr<200:
print cntr
C.move(currentPencil, -5, 0)
if ifDead()==True:
dead=True
break
cntr+=1
C.move(currentPencil, 1070, 0)
if currentPencil>=42 and currentPencil<=51:
C.move(currentPencil, 0, 70)
time.sleep(.5)
while cntr<200:
print cntr
C.move(currentPencil, 0, 5)
if ifDead()==True:
dead=True
break
cntr+=1
C.move(currentPencil, 0, -1070)
if currentPencil>=52 and currentPencil<=65:
C.move(currentPencil, 0, -70)
time.sleep(.5)
while cntr<200:
print cntr
C.move(currentPencil, 0, -5)
if ifDead()==True:
dead=True
break
cntr+=1
C.move(currentPencil, 0, 1070)
if dead:
top.destroy()
top = Tkinter.Tk()
C = Tkinter.Canvas(top, bg="light goldenrod", height=600, width=800)
#this below creates the background
C.create_line(760,41,760,559, fill="green")#light goldenrod
C.create_line(40,41,40,559, fill="blue")
C.create_line(41,40,759,40, fill="black")
C.create_line(41,560,759,560, fill="red")
C.create_line(0,100,1000,100, fill="deep sky blue")
C.create_line(0,150,1000,150, fill="deep sky blue")
C.create_line(0,200,1000,200, fill="deep sky blue")
C.create_line(0,250,1000,250, fill="deep sky blue")
C.create_line(0,300,1000,300, fill="deep sky blue")
C.create_line(0,350,1000,350, fill="deep sky blue")
C.create_line(0,400,1000,400, fill="deep sky blue")
C.create_line(0,450,1000,450, fill="deep sky blue")
C.create_line(0,500,1000,500, fill="deep sky blue")
C.create_line(0,550,1000,550, fill="deep sky blue")
C.create_line(0,600,1000,600, fill="deep sky blue")
C.create_line(75,0,75,1000, fill="red")
#this below creates the photos
rPencil = PhotoImage(file="H:\Computer Programming\Pencil right.gif")
lPencil = PhotoImage(file="H:\Computer Programming\Pencil left.gif")
tPencil = PhotoImage(file="H:\Computer Programming\Pencil top.gif")
bPencil = PhotoImage(file="H:\Computer Programming\Pencil bottom.gif")
paperpic = PhotoImage(file="H:\Computer Programming\paper2.gif")
paper = C.create_image(400,400, image = paperpic)
allPencils=[]
#ignore the one right under this
#lPencils-> -30x rPencils-> 830x tPencil-> -30y bPencil-> 630y
#all these below create the pencils out of bounds to later be moved into place
pencil1=C.create_image(-100, 66, image = lPencil, tags="Lpencil");allPencils.append(pencil1)
pencil2=C.create_image(-100, 118, image = lPencil, tags="Lpencil");allPencils.append(pencil2)
pencil3=C.create_image(-100, 170, image = lPencil, tags="Lpencil");allPencils.append(pencil3)
pencil4=C.create_image(-100, 222, image = lPencil, tags="Lpencil");allPencils.append(pencil4)
pencil5=C.create_image(-100, 274, image = lPencil, tags="Lpencil");allPencils.append(pencil5)
pencil6=C.create_image(-100, 326, image = lPencil, tags="Lpencil");allPencils.append(pencil6)
pencil7=C.create_image(-100, 378, image = lPencil, tags="Lpencil");allPencils.append(pencil7)
pencil8=C.create_image(-100, 430, image = lPencil, tags="Lpencil");allPencils.append(pencil8)
pencil9=C.create_image(-100, 482, image = lPencil, tags="Lpencil");allPencils.append(pencil9)
pencil10=C.create_image(-100, 534, image = lPencil, tags="Lpencil");allPencils.append(pencil10)
pencil11=C.create_image(900, 534, image = rPencil, tags="Rpencil");allPencils.append(pencil11)
pencil12=C.create_image(900, 482, image = rPencil, tags="Rpencil");allPencils.append(pencil12)
pencil13=C.create_image(900, 430, image = rPencil, tags="Rpencil");allPencils.append(pencil13)
pencil14=C.create_image(900, 378, image = rPencil, tags="Rpencil");allPencils.append(pencil14)
pencil15=C.create_image(900, 326, image = rPencil, tags="Rpencil");allPencils.append(pencil15)
pencil16=C.create_image(900, 274, image = rPencil, tags="Rpencil");allPencils.append(pencil16)
pencil17=C.create_image(900, 222, image = rPencil, tags="Rpencil");allPencils.append(pencil17)
pencil18=C.create_image(900, 170, image = rPencil, tags="Rpencil");allPencils.append(pencil18)
pencil19=C.create_image(900, 118, image = rPencil, tags="Rpencil");allPencils.append(pencil19)
pencil20=C.create_image(900, 66, image = rPencil, tags="Rpencil");allPencils.append(pencil20)
pencil21=C.create_image(66, -100, image = tPencil, tags="Tpencil");allPencils.append(pencil21)
pencil22=C.create_image(118, -100, image = tPencil, tags="Tpencil");allPencils.append(pencil22)
pencil23=C.create_image(170, -100, image = tPencil, tags="Tpencil");allPencils.append(pencil23)
pencil24=C.create_image(222, -100, image = tPencil, tags="Tpencil");allPencils.append(pencil24)
pencil25=C.create_image(274, -100, image = tPencil, tags="Tpencil");allPencils.append(pencil25)
pencil26=C.create_image(326, -100, image = tPencil, tags="Tpencil");allPencils.append(pencil26)
pencil27=C.create_image(378, -100, image = tPencil, tags="Tpencil");allPencils.append(pencil27)
pencil28=C.create_image(430, -100, image = tPencil, tags="Tpencil");allPencils.append(pencil28)
pencil29=C.create_image(482, -100, image = tPencil, tags="Tpencil");allPencils.append(pencil29)
pencil30=C.create_image(534, -100, image = tPencil, tags="Tpencil");allPencils.append(pencil30)
pencil31=C.create_image(586, -100, image = tPencil, tags="Tpencil");allPencils.append(pencil31)
pencil32=C.create_image(638, -100, image = tPencil, tags="Tpencil");allPencils.append(pencil32)
pencil33=C.create_image(690, -100, image = tPencil, tags="Tpencil");allPencils.append(pencil33)
pencil34=C.create_image(742, -100, image = tPencil, tags="Tpencil");allPencils.append(pencil34)
pencil35=C.create_image(66, 700, image = bPencil, tags="Bpencil");allPencils.append(pencil35)
pencil36=C.create_image(118, 700, image = bPencil, tags="Bpencil");allPencils.append(pencil36)
pencil37=C.create_image(170, 700, image = bPencil, tags="Bpencil");allPencils.append(pencil37)
pencil38=C.create_image(222, 700, image = bPencil, tags="Bpencil");allPencils.append(pencil38)
pencil39=C.create_image(274, 700, image = bPencil, tags="Bpencil");allPencils.append(pencil39)
pencil40=C.create_image(326, 700, image = bPencil, tags="Bpencil");allPencils.append(pencil40)
pencil41=C.create_image(378, 700, image = bPencil, tags="Bpencil");allPencils.append(pencil41)
pencil42=C.create_image(430, 700, image = bPencil, tags="Bpencil");allPencils.append(pencil42)
pencil43=C.create_image(482, 700, image = bPencil, tags="Bpencil");allPencils.append(pencil43)
pencil44=C.create_image(534, 700, image = bPencil, tags="Bpencil");allPencils.append(pencil44)
pencil45=C.create_image(586, 700, image = bPencil, tags="Bpencil");allPencils.append(pencil45)
pencil46=C.create_image(638, 700, image = bPencil, tags="Bpencil");allPencils.append(pencil46)
pencil47=C.create_image(690, 700, image = bPencil, tags="Bpencil");allPencils.append(pencil47)
pencil48=C.create_image(742, 700, image = bPencil, tags="Bpencil");allPencils.append(pencil48)
C.pack()
top.bind_all('<Key>', key)
top.after(1000,pencilAttack)
top.mainloop()
你不应该为此使用线程。在几乎所有 GUI 框架中，都有一个 "event loop" 线程分派用户输入事件并更新 UI。如果您尝试从不同的线程更新 UI，将不会有任何好事发生。如果你幸运的话，框架会抓住你并抛出一个错误告诉你不要这样做，否则你最终会遇到难以调试的竞争条件。
我建议您立即执行操作，然后使用 top.after(500, pencilAttack).
顺便说一句，在 gui 程序中使用线程的唯一原因是在后台执行繁重的阻塞工作，例如从网络加载资源或进行某种 CPU 密集计算。在这种情况下，您的 GUI 框架将提供用于将函数调用从后台线程发布到应用程序线程的方法。