Python:在创建dict时用作dict值时调用方法

Question

我希望有一个带有方法的调度程序dict {str:method}.我想迭代调度程序键并将值作为方法调用,但是当我运行Python脚本时,一旦创建了dict,方法就会被执行:

from python.helper.my_client import Client

def deco_download(f):
    def f_download(*args, **kwargs):
        # some retry functionality here
        return json_data
    return f_download 

class Downloader:
    def __init__(self):
        self.attribute = 'some_value'

    @deco_download
    def download_persons(self, client, *args, **kwargs):
        return client.get_persons(*args, **kwargs)

    @deco_download
    def download_organizations(self, client, *args, **kwargs):
        return client.get_organizations(*args, **kwargs)

def run(self):
    dispatcher = {
        'person': self.download_persons(client),
        'organization': self.download_organizations(client)
    }

    for key in dispatcher:
        print("Downlading data for: {0}".format(key)
        dispatcher[key]

不幸的是,在我在for循环中调用它们之前初始化调度程序dict时,这些方法是直接执行的.我希望它们可以在for循环中调用,而不是在dict构造期间调用.我在这做错了什么？是因为我正在使用装饰器吗？

Answer 1

他们被叫,因为你打电话给他们.不要那样做; 把咒语放在字典中.

def run(self):
    dispatcher = {
        'person': self.download_persons,
        'organization': self.download_organizations
    }

    for key in dispatcher:
        print("Downlading data for: {0}".format(key)
        dispatcher[key](client)