在另一个函数中使用返回值

Question

我有两个功能.请参阅以下功能;

 def check_channel_number(self):

    print "***************Channel Checker *********************" 

    print ''

    user_channel_number = int(re.sub('\D', '', raw_input("Enter a channel number, (3digit): "))[:3]);

    channel = ("channelNr= '%d'") % (user_channel_number)

    print channel

    # channel_search = channel + str(user_channel_number)

    datafile = file('output.txt')

    found = False

    for line in datafile:

        if channel in line:

            found = True 
            print 'The channel number you entered is correct and will be deleted'
            return user_channel_number

    print 'The channel number you entered is not on the planner'
    return False

只想在以下函数中使用(user_channel_number)的返回值.

   def delete_events(self):



    if user_channel_number == True:

        return 'The program number is correct and will be deleted'

        # action = 'DeleteEvent'
        menu_action = 'all'
        book = 'RECYC:687869882'
        arg_list = [('C:\\Users\\yke01\\Documents\\StormTest\\Scripts\\Completed'
                        '\\Utils\\UPNP_Client_Cmd_Line.py')]
        arg_list.append(' --action=')
        arg_list.append(action)
        arg_list.append(' --ip=')
        arg_list.append('10.10.8.89')
        arg_list.append(' --objectId=')
        arg_list.append(book)

        subprocess.call(["python", arg_list])

        print 'The program deleted successfully'

当我运行我的脚本时,它说user_channel_number没有全局定义？我user_channel_number该如何调用delete_events()函数内部？

Answer 1

当您在函数内部定义变量时,它是一个局部变量,这意味着它只能在该函数中访问.

在一个班级内

看起来你在一个类中,所以你可以通过这样定义它来使类中的所有方法都可以访问该变量:

def check_channel_number(self):

    self.user_channel_number = ...

然后在第二个函数中,您可以像下面这样使用它:

def delete_events(self):

    if self.user_channel_number:

课外

如果您没有在类中使用方法,则可以使用global内置函数.

例如,

def check_channel_number():

    global user_channel_number 
    user_channel_number = ...

def delete_events():

    if user_channel_number:

        ...

使用函数返回的值

而不是在你的第一个函数中check_channel_number(),你可以让它返回user_channel_number.然后,您可以在其中调用该函数delete_events(),如下所示:

def check_channel_number():

    user_channel_number = ...
    return user_channel_number

def delete_events():

    if check_channel_number():

        ...

Answer 2

函数不能共享其局部变量。您可以从第一个返回值，然后将其传递给第二个：

def check_channel_number(self):
    ...
    return user_channel_number

def delete_events(self):
    user_channel_number = self.check_channel_number()
    ...

或在对象上保存值：

def check_channel_number(self):
    ...
    self.user_channel_number = user_channel_number
    ...

def delete_events(self):
    if self.user_channel_number:
         ....