字典python中的问题 [英] problem in dictionary python

问题描述

我制作了一个字典，然后将值和键分成列表，现在看起来像这样:

I made a dictionary, then split up the values and keys into lists and now its looks like this:

keys = [(4,5),(5,6),(4,8)......so on].
values = [('west',1),('south',1).......]

然后我像这样制作了新字典，

Then I made a new dictionary like in this way,

final = dict((k,v[0]) for k,v in zip(keys, values))

当我执行-print final时-输出是这种形式... {(4,5):west,(5,6):south,......so on}

When I execute -print final - output is in this form... {(4,5):west,(5,6):south,......so on}

现在我需要具有键(4,5)的值...它可以是任何键..

Now i need to have the value of key (4,5)...it can be any key..

q:2

win = gap.pop() - here gap is a stack
         print win      - the output is (1,1)
         return final.get(win) -

但是当我返回时，它给了我一个错误，最后是我用键和值列表创建的目录

but when I do this return, it gives me an error and final is the directory that I have made with lists of keys and values

错误是:"W"

推荐答案

为我工作:

>>> final = {(4,5):"West", (5,6): "East"}
>>> print final
{(4, 5): 'West', (5, 6): 'East'}
>>> final[(4,5)]
'West'

您可能想尝试final.get((4,5)).

或发布更多代码，也许您喜欢final做些什么.如果您没有找回价值，则至少应该得到一个KeyError:

Or post more code, maybe you do something fancy with final. If you don't get a value back, you should at least get a KeyError:

>>> final[(7,8)]
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
KeyError: (7, 8)

在这种情况下，您要么必须处理异常:

In this case you either have to handle the exception:

try:
    final[(7,8)]
except KeyError:
    print "Key not in dict."

或使用final.get((7,8), <default value>)，如果找不到密钥，则返回<default value>(如果未指定默认值，则返回None).

or use final.get((7,8), <default value>) which will return <default value> if the key is not found (or None if you don't specify a default value).

> 在Python文档中了解字典 > .

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