To use **kwargs in Python, you can define a function using the ** syntax in the function definition. Here’s an example:
def my_function(**kwargs):
for key, value in kwargs.items():
print(f'{key}: {value}')
my_function(param1='value1', param2='value2')
This defines a function my_function with a **kwargs parameter that allows it to accept an arbitrary number of keyword arguments. The function then loops through the kwargs dictionary and prints the key-value pairs.
When calling the function, you can pass any number of keyword arguments:
my_function(param1='value1', param2='value2')
This will output:
param1: value1
param2: value2
You can also use the ** syntax to unpack a dictionary into keyword arguments when calling a function:
my_dict = {'param1': 'value1', 'param2': 'value2'}
my_function(**my_dict)
This will output:
param1: value1
param2: value2
**kwargs can be used in a class definition
**kwargs can be used in a class definition just like in any other function definition. Here’s an example:
class Example:
def __init__(self, **kwargs):
self.__dict__.update(kwargs)
example = Example(param1="value1", param2="value2")
print(example.param1) # "value1"
print(example.param2) # "value2"
In this example, we define a class Example that has an __init__ method that accepts any number of keyword arguments using the **kwargs syntax. Inside the __init__ method, we update the instance’s __dict__ with the keyword arguments passed in, so that they are stored as instance variables.
You can then create an instance of the class and pass in any number of keyword arguments:
example = Example(param1="value1", param2="value2")
And you can access the instance variables like this:
print(example.param1) # "value1"
print(example.param2) # "value2"