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Assigning 无Type to Dict in-030
原标题:Assigning NoneType to Dict in Python

I m 试图将None分配给一个字典中的钥匙,但Im 正在获得一个字体:

self._rooms[g[0]] = None
TypeError:  NoneType  object does not support item assignment

我的法典在这里是:

r = open(filename,  rU )
    for line in r:
        g = line.strip().split( , )
        if len(g) > 1:
            r1 = g[0]
            h = Guest(g[1], str2date(g[2]), str2date(g[3]))
            self._rooms.set_guest(r1, h)
        else:
            self._rooms[g[0]] = None
    r.close()

在此之前,我要说的是,它不是赢得的。 这是奇怪的。

问题回答

例外情况明确如下: 无 物体类型不支持项目,这意味着<代码>本身._rooms 实际上是None

Edit: As you said yourself

self._rooms = {} 

self._rooms = dict()

你们需要做些什么来清除dict子。

核对<代码>本身._rooms is not None

签署<条码>None,作为<条码>的数值 关键实际工作:

In [1]: dict(a=None)
Out[1]: { a : None}

从阅读你对Jakob的评论来看,我发现,主犯是这条线(没有张贴)。

d = self._rooms 
self._rooms = d.clear()

d.clear() will clear the dictionary d (and self._rooms) in place and return None. Thus, all said an done, d is an empty dictionary and self._rooms is None.

最为清洁的解决办法是:

self._rooms.clear()  #No need for assignment here!

尤其是自<条码>以来,似乎已继承<条码>。 因此,它可能具有其他特征,你不想这样做:

self._rooms={}  #Now this is just a dict, no longer has `set_guest` method!

也许有人抱怨<代码>本身._rooms,我怀疑是None

我的错误如下:

类型:无 类型物体不支持项目转让

因为我对<代码>分配了价值。 无类型,关键如下:

x = None
x[ y ] = "Hello" # Here

为了解决这一错误,我把价值计算到<条码>。 类型如下:

x = {}
x[ y ] = "Hello" # Here
x = dict()
x[ y ] = "Hello" # Here




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