所以我正在制作一个程序，它调用一个函数来进行一些计算，并且有按钮可以按下来改变输入并重新计算。
效果很好，除非在计算完成之前按下按钮，否则会计算并输出新值，然后再返回到先前的值。基本上，程序执行我想要的操作，除了按下按钮并完成第二次计算后返回第一次计算（所有变量值都返回）。
问题的一般示意图： 1.根主循环 2.输入的值 3.按＆＃39; Go＆＃39; 4.打印到屏幕上的计算（顺便说一下Monty Carlo sim） 5.按按钮更改输入值 6.打印到屏幕上的新计算 7.一旦新的变量完成，旧变量值的计算将返回完成
有没有办法阻止python返回到之前的变量值？我希望有一种方法可以返回主循环，以便屏幕上的计算保持正确。谢谢！
编辑： 这是代码（抱歉它有点长，这是我第一次使用tkinter）：
from tkinter import *
from tkinter import ttk
from random import *
from statistics import *
from math import *
'''
Prompt user for: number attacking with, number of defenders at each space
Output: n approaching 100000 and error range approaching .3%, probabilities of next roll, probabilities of winning at each spot, average number of pieces lost & stddev,buttons for decreasing defender/attacker
'''
def reset():
attacker_entry.delete(0,END)
for i in range(len(spaces_entry)):
spaces_entry[i].delete(0,END)
update_buttons()
def update_buttons(*args):
buttons = [attacker_2,attacker_1,split_button,defender_1,defender_2]
try:
if int(attacker_entry.get()) > 1:
for button in buttons:
button['state'] = ['normal']
elif int(attacker_entry.get()) == 1:
attacker_2['state'] = ['disabled']
split_button['state'] = ['disabled']
elif int(attacker_entry.get()) == 0:
for button in buttons:
button['state'] = ['disabled']
return
if int(space1_entry.get()) > 1:
defender_2['state'] = ['normal']
elif int(space1_entry.get()) == 1:
defender_2['state'] = ['disabled']
split_button['state'] = ['disabled']
except:
for button in buttons:
button['state'] = ['disabled']
def subtract(label,*args):
if label == "both":
label = "att def 1"
end = int(label[-1:])
if "att" in label:
attacker_amount.set(int(attacker_entry.get()) - end)
if "def" in label:
space1.set(int(space1_entry.get()) - end)
if int(space1_entry.get()) == 0:
attacker_amount.set(int(attacker_entry.get()) - 1)
for i in range(len(spaces)):
try:
spaces[i].set(int(spaces_entry[i+1].get()))
except:
spaces[i].set("")
win_avgs[i].set("")
pieces_left[i].set("")
most_likely[i].set("")
space10.set("")
update_buttons()
go()
def check_if_multiple(list1,list2):
if len(list1)>1 and len(list2)>1:
ret_val = 2
else:
ret_val = 1
return ret_val
def set_rolls(total,limit):
list = []
for i in range(total):
if len(list) < limit:
list.append(randrange(1,7))
return list
def go(*args):
update_buttons()
try:
attacker_total = int(attacker_entry.get())
except:
return
defender_pieces_list = []
for entry in spaces_entry:
try:
new_val = int(entry.get())
if new_val == 0:
None
else:
defender_pieces_list.append(new_val)
except:
None
defender_total_spaces = len(defender_pieces_list)
attacker_total_original = attacker_total
total_trials = 10000
defender_losses = 0
attacker_losses = 0
first_round_defender_total_wins = 0
first_round_attacker_total_wins = 0
first_round_split_total = 0
space1_succ,space2_succ,space3_succ,space4_succ,space5_succ,space6_succ,space7_succ,space8_succ,space9_succ,space10_succ = [],[],[],[],[],[],[],[],[],[]
space1_all,space2_all,space3_all,space4_all,space5_all,space6_all,space7_all,space8_all,space9_all,space10_all = [],[],[],[],[],[],[],[],[],[]
succ_list = [space1_succ,space2_succ,space3_succ,space4_succ,space5_succ,space6_succ,space7_succ,space8_succ,space9_succ,space10_succ]
all_list = [space1_all,space2_all,space3_all,space4_all,space5_all,space6_all,space7_all,space8_all,space9_all,space10_all]
for trial in range(total_trials):
if trial%20 == 0:
for i in range(0,defender_total_spaces):
try:
win_avgs[i].set(round(((len(succ_list[i]))/trial)*100,1))
pieces_left[i].set(str(round(mean(all_list[i]),2)))
most_likely[i].set(mode(all_list[i]))
root.update()
except:
None
attacker_total = attacker_total_original
first_round = True
for i in range(defender_total_spaces):
defender_total = defender_pieces_list[i]
while defender_total>0 and attacker_total > 0:
defender_win = False
attacker_win = False
defender_rolls_list = set_rolls(defender_total,2)
attacker_rolls_list = set_rolls(attacker_total,3)
if len(attacker_rolls_list) == 1:
defender_rolls_list = [randrange(1,7)]
for j in range(check_if_multiple(defender_rolls_list,attacker_rolls_list)):
if max(defender_rolls_list)>=max(attacker_rolls_list):
attacker_total += -1
defender_win = True
else:
defender_total += -1
attacker_win = True
attacker_rolls_list.remove(max(attacker_rolls_list))
defender_rolls_list.remove(max(defender_rolls_list))
if first_round == True:
if defender_win == True and attacker_win == True:
first_round_split_total += 1
elif attacker_win == True:
first_round_attacker_total_wins += 1
elif defender_win == True:
first_round_defender_total_wins += 1
first_round = False
if defender_total == 0:
succ_list[i].append(attacker_total)
all_list[i].append(attacker_total)
if attacker_total == 1:
attacker_total == -1
if attacker_total == 0:
all_list[i].append(attacker_total)
attacker_total += -1
for i in range(0,defender_total_spaces):
try:
win_avgs[i].set(round(((len(succ_list[i]))/trial)*100,1))
pieces_left[i].set(str(round(mean(all_list[i]),2))+"("+str(round(stdev(all_list[i]),1))+")")
most_likely[i].set(mode(all_list[i]))
except:
None
height = 450
width = 600
shape = str(width) + "x" + str(height)
root = Tk()
root.title("Risk Probability Calculator")
root.geometry(shape)
content = ttk.Frame(root)
content.grid(column=0, row=0, sticky=(N, W, E, S))
content.columnconfigure(0, weight=1)
content.rowconfigure(0, weight=1)
title = ttk.Label(content, text="Risk Probability Calculator", relief="ridge", background="gray",font=("TkHeadingFont",20),anchor="center")
title.grid(column=1, row=1, columnspan=8, padx=3, pady=4,sticky=(N,W,E,S))
reset_button = ttk.Button(content, text="Reset", command=reset)
reset_button.grid(column=1, row=2,padx=3, pady=4, sticky=(N, W, E, S))
go_button = ttk.Button(content, text="Go", command=go)
go_button.grid(column=2, row=2,padx=3, pady=4, sticky=(N, W, E, S))
ttk.Label(content, text="Attacking with:").grid(column=1, row=3,padx=3, pady=4, sticky=(NW))
ttk.Label(content, text="Defending with:").grid(column=1, row=4,padx=3, pady=4, sticky=(NW))
for i in range(5,15):
text = "Space " + str(i-4) + ":"
ttk.Label(content, text=text).grid(column=1,padx=3, pady=4, row=i, sticky=(N,E,S))
attacker_amount = StringVar()
attacker_entry = ttk.Entry(content, textvariable=attacker_amount, width=4)
attacker_entry.grid(column=2, row=3,padx=3, pady=4, sticky=(N, W, S))
spaces = []
spaces_entry = []
for i in range(1, 11):
globals()['space'+str(i)] = StringVar()
spaces.append(globals()['space'+str(i)])
globals()['space'+str(i)+'_entry'] = ttk.Entry(content, textvariable=spaces[i-1], width=4)
globals()['space'+str(i)+'_entry'].grid(column=2, row=(i+4),padx=3, pady=4, sticky=(N, W, S))
spaces_entry.append(globals()['space'+str(i)+'_entry'])
attacker_2 = Button(content, text="Attacker -2",command=lambda: subtract("att 2"))
attacker_2.grid(column=4, row=2,padx=3, pady=4, sticky=(N,W,E,S))
attacker_1 = Button(content, text="Attacker -1",command=lambda: subtract("att 1"))
attacker_1.grid(column=5, row=2,padx=3, pady=4, sticky=(N,W,E,S))
split_button = Button(content, text="Split",command=lambda: subtract("both"))
split_button.grid(column=6, row=2,padx=3, pady=4, sticky=(N,W,E,S))
defender_1 = Button(content, text="Defender -1",command=lambda: subtract("def 1"))
defender_1.grid(column=7, row=2,padx=3, pady=4, sticky=(N,W,E,S))
defender_2 = Button(content, text="Defender -2",command=lambda: subtract("def 2"))
defender_2.grid(column=8, row=2,padx=3, pady=4, sticky=(N,W,E,S))
ttk.Separator(content,orient="vertical").grid(column=3,row=2,rowspan=15,padx=3, pady=4,sticky=(N,W,E,S))
results_frame = ttk.Labelframe(content, text='Results:')
results_frame.grid(column=4, row=3, columnspan=5, rowspan=12,padx=3, pady=4, sticky=(N,W,E,S))
pane = ttk.Panedwindow(results_frame, orient='horizontal')
pane.grid(column=1,row=1,columnspan=5,padx=3,sticky=(N,W,E,S))
pane1 = ttk.Labelframe(pane)
pane.add(pane1)
Label(pane1,text="% Win").grid(column=1,row=1,sticky=(N,W,E))
win_avgs = []
for i in range(1,11):
globals()['win_avg'+str(i)] = StringVar()
win_avgs.append(globals()['win_avg'+str(i)])
Label(pane1,textvariable=win_avgs[i-1]).grid(column=1,row=i+1,padx=4, pady=4,sticky=(N,W,S))
pane2 = ttk.Labelframe(pane)
pane.add(pane2)
Label(pane2,text="Pieces Left").grid(column=1,row=1,sticky=(N,W,E))
pieces_left = []
for i in range(1,11):
globals()['pieces_left'+str(i)] = StringVar()
pieces_left.append(globals()['pieces_left'+str(i)])
Label(pane2,textvariable=pieces_left[i-1]).grid(column=1,row=i+1,padx=4, pady=4,sticky=(N,W,S))
pane3 = ttk.Labelframe(pane)
pane.add(pane3)
Label(pane3,text="Most likely # of Pieces Left").grid(column=1,row=1,sticky=(N,W,E))
most_likely = []
for i in range(1,11):
globals()['most_likely'+str(i)] = StringVar()
most_likely.append(globals()['most_likely'+str(i)])
Label(pane3,textvariable=most_likely[i-1]).grid(column=1,row=i+1,padx=4, pady=4,sticky=(N,W,S))
root.mainloop()
答案 0 :(得分：0)
简短的回答是，这是因为你致电root.update()。这不仅会重绘屏幕，还会处理任何待处理的事件。一个好的经验法则是“从不打电话给update”这个确切的原因。您很少必须，但通常有更好的方法来组织您的代码。如果你在一个只需要几毫秒的函数中执行它，你有时可以使用它，但看起来你的函数计算了很多东西。如果用户按下某个键或单击按钮然后调用update，则tkinter将尝试在继续之前处理该事件。
我建议先删除电话，看看会发生什么。如果屏幕似乎冻结（考虑到您尝试运行多少代码，可能会冻结），您可以尝试将其替换为root.update_idletasks()。这不会处理任何点击或按钮事件，只会处理某类事件，例如“重新绘制屏幕”。