创建具有列表理解的字典 [英] Create a dictionary with list comprehension

问题描述

我喜欢Python列表理解语法.

I like the Python list comprehension syntax.

它也可以用来创建字典吗?例如，通过遍历键和值对:

Can it be used to create dictionaries too? For example, by iterating over pairs of keys and values:

mydict = {(k,v) for (k,v) in blah blah blah}  # doesn't work

推荐答案

从Python 2.7和3开始，您应该只使用

From Python 2.7 and 3 onwards, you should just use the dict comprehension syntax:

{key: value for (key, value) in iterable}

在Python 2.6和更早版本中，内置的dict可以接收键/值对的迭代，因此您可以将其传递给列表推导或生成器表达式.例如:

In Python 2.6 and earlier, the dict built-in can receive an iterable of key/value pairs, so you can pass it a list comprehension or generator expression. For example:

dict((key, func(key)) for key in keys)

但是，如果您已经具有可迭代的键和/或val，则根本不需要使用理解-最简单的方法是直接调用内置的dict:

However if you already have iterable(s) of keys and/or vals, you needn't use a comprehension at all - it's simplest just call the dict built-in directly:

# consumed from any iterable yielding pairs of keys/vals
dict(pairs)

# "zipped" from two separate iterables of keys/vals
dict(zip(list_of_keys, list_of_values))

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