2.6. Function¶
2.6.1. **kwargs: Pass Multiple Arguments to a Function in Python¶
Sometimes you might not know the arguments you will pass to a function. If so, use **kwargs.
**kwargs allow you to pass multiple arguments to a function using a dictionary. In the example below, passing **{'a':1, 'b':2} to the function is similar to passing a=1, b=1 to the function.
Once **kwargs argument is passed, you can treat it like a Python dictionary.
parameters = {'a': 1, 'b': 2}
def example(c, **kwargs):
print(kwargs)
for val in kwargs.values():
print(c + val)
example(c=3, **parameters)
{'a': 1, 'b': 2}
4
5
2.6.2. Decorator in Python¶
Do you want to add the same block of code to different functions in Python? If so, try decorator.
In the code below, I created the decorator to track the time of the function say_hello.
import time
def time_func(func):
def wrapper():
print("This happens before the function is called")
start = time.time()
func()
print('This happens after the funciton is called')
end = time.time()
print('The duration is', end - start, 's')
return wrapper
Now all I need to do is to add @time_func before the function say_hello.
@time_func
def say_hello():
print("hello")
say_hello()
This happens before the function is called
hello
This happens after the funciton is called
The duration is 0.0002987384796142578 s
Decorator makes the code clean and shortens repetitive code. If I want to track the time of another function, for example, func2(), I can just use:
@time_func
def func2():
pass
func2()
This happens before the function is called
This happens after the funciton is called
The duration is 4.38690185546875e-05 s
from typing import List, Dict
def