Pass dictionaries in function as arguments
Im trying to create a function that take unknown number of arguments (dictionaries) to merge them in one. Here is my sketch:
weight = {"sara": 60, "nick": 79, "sem": 78, "ida": 56, "kasia": 58, "slava": 95}
height = { "a" : 1, "b": 2, "c":3 }
width = {"u": "long", "q": 55, "qw": "erre", 30: "34"}
a = {10:20, 20:"a"}
def merge(**dict):
new_dict = {}
for x in dict:
for a, b in x.items():
new_dict[a] = b
return new_dict
print(merge(weight, height, width, a))
And I got error:
TypeError: merge() takes 0 positional arguments but 4 were given
Why?
Change def merge(**dict):
to def merge(*dict):
and it is working. Avoid naming it dict
since it is a keyword in python.
First note: dict
is a bad name for an argument as it is already the name of a type.
When you use **
in the argument list for a function it is slurping up any keyword arguments you haven't explicitly listed. Similarly, a parameter with a single *
is slurping up any extra positional arguments not explicitly named.
Consider:
>>> def foo(bar, **baz): return (bar, baz)
...
>>> foo(42, wooble=42)
(42, {'wooble': 42})
>>> foo(bar=42, wooble=42)
(42, {'wooble': 42})
>>> foo(bar=42, wooble=42, hello="world")
(42, {'wooble': 42, 'hello': 'world'})
>>>
If you wish to take any number of dictionaries as arguments, you'd use:
def merge(*dicts):
...
As dicts
will now slurp up any number of dictionaries passed in.