Question

我有一个带有全局变量的Python文件并定义了一个类：

ROOT = 'https://api.example.com/2.0/'

class Mail(object):
    def __init__(self, api_key):
        self.name = "FName"

        if api_key.find('-'):
            dc = api_key.split('-')[1]

        global ROOT
        print "initing root to: %s" % (ROOT,)
        ROOT = ROOT.replace('https://api.', 'https://'+dc+'.api.')
        print "initing after replace of ROOT: %s" % (ROOT,)

    def pprint(self):
        print 'POST to %s' % (ROOT,)

ROOT全局似乎一旦设置就不会更新：

>>> import pyglob 
>>> mc = pyglob.Mail('dfadsfad-us1')
initing root to: https://api.example.com/2.0/
initing after replace of ROOT: https://us1.api.example.com/2.0/
>>> mc.pprint()
POST to https://us1.api.example.com/2.0/
>>> mc3 = pyglob.Mail('dfadsfad-us3')
initing root to: https://us1.api.example.com/2.0/
initing after replace of ROOT: https://us1.api.example.com/2.0/
>>> mc3.pprint()
POST to https://us1.api.example.com/2.0/
>>> mc.pprint()
POST to https://us1.api.example.com/2.0/

有人可以解释一下这是如何工作的以及它为什么会发生？

Answer 1

完成ROOT = https://us1.api.example.com/2.0/后，ROOT.replace('https://api.', 'https://'+dc+'.api.')无法执行任何操作，因为'https://api.'已不在ROOT - 您已替换它。

这整个情况看起来非常混乱，你可能想要重构这一点，而不是重新绑定全局变量。

Python全局不在新对象实例中更新

1 个答案: