Python函数参数：tuple / list [英] Python function parameter: tuple/list

问题描述

我的函数需要一个列表或一个元组作为参数。它不是真正关心它是什么，它所做的是将它传递给另一个接受列表或元组的函数：

  def func（arg）：＃arg is tuple or list 
 another_func（x）
＃do other stuff here 
  

现在我需要稍微修改函数，以处理一个额外的元素：

  def func （arg）：#arg is tuple or list 
 another_func（x + ['a']）
＃etc 
  

$ b不幸的是这不会工作：如果arg是元组，我必须说 x +（'a'，）。

显然，我可以通过强制arg列表来使它工作。但它不整洁。

有更好的方法吗？

解决方案

如果我们不能通过一个元组， another_func 只是想要一个迭代器，你可以传递 itertools.chain（x，'a'） >

My function expects a list or a tuple as a parameter. It doesn't really care which it is, all it does is pass it to another function that accepts either a list or tuple:

def func(arg): # arg is tuple or list
  another_func(x)
  # do other stuff here

Now I need to modify the function slightly, to process an additional element:

def func(arg): #arg is tuple or list
  another_func(x + ['a'])
  # etc

Unfortunately this is not going to work: if arg is tuple, I must say x + ('a',).

Obviously, I can make it work by coercing arg to list. But it isn't neat.

Is there a better way of doing that? I can't force callers to always pass a tuple, of course, since it simply shifts to work to them.

解决方案

If another_func just wants a iterable you can pass itertools.chain(x,'a') to it.

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