Some Cool Python Features 🌱

Last updated on March 13, 2021

Dataclasses

import dataclasses

@dataclasses.dataclass
class FruitBasket:
	fruits: List[str]
	basket_type: str

Operator Overloading

@dataclasses.dataclass
class FruitBasket:
	fruits: List[str]
	basket_type: str

def __add__(self, other_basket: FruitBasket):
    return FruitBasket(fruits=self.fruits + other_basket.fruits, basket_type="multiple baskets")

my_basket = FruitBasket(["banana", "orange", "apple"], "wicker")
michael_basket = FruitBasket(["clementine", "lemon", "peach"], "wicker")
combined_basket = my_basket + michael_basket
combined_basket

Outputs:

FruitBasket(fruits=\['banana', 'orange', 'apple', 'clementine', 'lemon', 'peach'\], basket\_type='multiple baskets')

Can do this with a bunch of different operations: <, >, ==, >=, <=, len(), [], bool()

Decorators

def smart_divide(func):
    def inner(a, b):
        print("I am going to divide", a, "and", b)
        if b == 0:
            print("Whoops! cannot divide")
            return
        return func(a, b)
    return inner

This nested function smart_divide takes in an input function func and then creates a function around it called inner which it returns. inner is a function object itself.

In order to apply this decorator function on something there are wo ways that are equivalent:

1

def divide(a, b):
	print(a/b)

inner_func = smart_divide(divide)
inner_func(1,2)

Create function divide
The nested function smart_divide takes in this divide function and returns the inner function object. This object can be called normally like any other function
2

` @smart_divide def divide(a, b): print(a/b)

divide(1,2)

This is equivalent to the above method.
1. `smart_divide` sets `divide` to be the function `inner`.  So now whenever `divide` is called, it is actually the inner function of `smart_divide` that's being called.


### Abstract Base Classes

import abc import pandas as pd

class MyClass(abc.ABC):
@abc.abstractmethod
def some_function1(self, arg1: list, arg2: pd.DataFrame) -> pd.DataFrame:
pass

@abc.abstractmethod  
 	def some_function2(self, arg1: pd.Series, arg2: int, arg3: str):  
	pass ```

Any class that inherits from MyClass is required to declare the functions that have the @abc.abstractmethod decorator. We can just specify the types that the function takes, and the functions we declare must have the same types.

Notes mentioning this note

There are no notes linking to this note.

Here are all the notes in this garden, along with their links, visualized as a graph.