Question

假设我写了这样的程序。

# run the program until the user gives a "stop" input
usrinpt=""`
n=1
while usrinpt!="stop":
    n+=1
    ---- do-something -----
    ---- do-something -----
    ---- do-something -----
print n # print the number of loops it has gone through.

现在程序将一直运行，直到我手动将参数usrinpt更改为＆＃34;停止＆＃34;。但是使用raw_input将在每个步骤停止模拟，这不是我想要的。

那么，有没有办法在不停止模拟的情况下更改usrinpt？

Answer 1

您可以捕获KeyboardInterrupt例外：

from __future__ import print_function # Python 2/3 compatibility

n = 1
try:
   while True:
       n += 1
except KeyboardInterrupt:
    print('\nnumber of loops', n)

当用户键入<CTRL>-<C>时，程序会打印迭代次数并继续。

Answer 2

使用线程的更复杂的解决方案：

describe MyClass do
  before { @my_class = MyClass.new }
    describe '#update' do
      it 'should correctly update the value' do
        @my_class.update('some_value')
        expect(@my_class.ary).to equal(['some_value'])

示例程序运行：

from __future__ import print_function # Python 2/3 compatibility

import sys
from time import sleep
from threading import Thread

if sys.version_info.major < 3:
    input = raw_input

def do_something():
    # doing the work
    sleep(1)

usrinpt = ''

def main():
    n = 1
    while usrinpt != 'stop':
        n += 1
        do_something()
    print('\nnumber of loops', n)

thread = Thread(target=main)
thread.start()

while True:
    print('Enter "stop" to terminate program')
    usrinpt = input().strip().lower()
    if usrinpt == 'stop':
        break

thread.join()

如何在不停止程序的情况下更改参数

2 个答案: