How does keys method work for dictionaries in python-CodePudding

How does .keys method return a list of keys in parenthesis? I mean after getting a list of keys how does python put this list into parenthesis? If I want to write a function that returns list in parenthesis how should I implement that? For example: def foo(): l=[1,2] what should I write so that when I call my function it returns this list l in parenthesis? Thanks in advance

CodePudding user response：

It looks like you might be new to Python. If what you want to do is return a tuple (1, 2) from a list var =[1, 2] you can apply the tuple() function:

>>> var = tuple([1, 2])
>>> var
(1, 2)

In actual fact the dict.keys() fujnction returns a special iterator called a view, but as the tuple function takes any iterator as an argument the tuple function will still work for a view.

>>> d = {1: 'one', 2: 'two'}
>>> tuple(d.keys()
(1, 2)

If this isn't what you want perhaps you can edit the question to explain more clearly what you are trying to do.

CodePudding user response：

def foo(l):

  return tuple(l.keys())

A simple test to check the result:

print(foo({1:"one", 2: "two"}))

print(foo({1:"one", 2:"two", 3:"three", 4:"four", "anykey":"anyvalue"}))