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Python Object-Oriented Python (retired) Inheritance Intro to Inheritance

Parimal Raghavan
PLUS
Parimal Raghavan
Courses Plus Student 1,940 Points
Posted by Parimal Raghavan
Parimal Raghavan
Courses Plus Student 1,940 Points

Can someone explain what this for loop does?

for key, values in kwarg.items():
    setattr(self, key, value).

What exactly does this do?

[MOD: added ```python markdown formatting]

1 Answer

Chris Freeman
MOD
Chris Freeman
Treehouse Moderator 68,454 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,454 Points

When a function is defined using **kwargs as a parameter, it will accept an arbitrary number of keyword arguments. These arguments are assigned in a dict-like object where the argument names are the dict keys and the argument values are the dict values. The code parses the keyword arguments and set local object attributes.

# for each key and value pair in the kwargs dict
for key, values in kwargs.items():
    # set the local attribute of this object
    # where the attribute name is the 'key' and the attribute value is the 'value'
    setattr(self, key, value).

Post back if your need more details

Nursultan Bolatbayev
Nursultan Bolatbayev
16,774 Points
Nursultan Bolatbayev
Nursultan Bolatbayev
16,774 Points

But why we cant do it without .items() function? For example when we run a loop for dictionary we dont use it, right?

Chris Freeman
Chris Freeman
Treehouse Moderator 68,454 Points
Chris Freeman
Chris Freeman
Treehouse Moderator 68,454 Points

Using .items() is one of many ways to iterate over a dict. When not explicitly using a method, as in:

for item in some_dict:

This default method is to iterate over the keys of the dict. The equivalent statement written explicitly:

for item in some_dict.keys():

The third method available is .values() which iterates over the values in a dict.

Back to the question, using .items() is a matter of convenience to retrieve both the key and value together. The solution could be rewritten as:

# for each key in the kwargs dict
for key in kwargs:
    # get the value
    value = kwargs[key]
    # set the local attribute of this object
    # where the attribute name is the 'key' and the attribute value is the 'value'
    setattr(self, key, value).