对于一个case/switch语句，Python等价于什么?(复制)

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Replacements for switch statement in Python? 47 answers
在Python中替换switch语句?47个答案

I'd like to know, is there a Python equivalent for the case statement such as the examples available on VB.net or C#?

我想知道，对于case语句来说，是否存在与Python等价的语句，比如VB.net或c#上的示例?

2 个解决方案

#1

377

While the official docs are happy not to provide switch, I have seen a solution using dictionaries.

虽然官方文档很乐意不提供交换机，但我看到了使用字典的解决方案。

For example:

例如:

# define the function blocks
def zero():
    print "You typed zero.\n"

def sqr():
    print "n is a perfect square\n"

def even():
    print "n is an even number\n"

def prime():
    print "n is a prime number\n"

# map the inputs to the function blocks
options = {0 : zero,
           1 : sqr,
           4 : sqr,
           9 : sqr,
           2 : even,
           3 : prime,
           5 : prime,
           7 : prime,
}

Then the equivalent switch block is invoked:

然后调用等效开关块:

options[num]()

This begins to fall apart if you heavily depend on fall through.

如果你严重依赖失败，这将开始崩溃。

#2

The direct replacement is if/elif/else.

直接替换为if/elif/else。

However, in many cases there are better ways to do it in Python. See "Replacements for switch statement in Python?".

然而，在许多情况下，有更好的方法在Python中实现它。参见“在Python中替换switch语句?”

#1

377