Dependency inversion

# line 6, CurrencyConverter is subclass of high-level AbatractBaseClass ABC  
# line 16, AlphaConverter is subclass of CurrencyConverter 
# line 32, App is dependent of above high-level class i.e. dependency inversion 
from abc import ABC

class CurrencyConverter(ABC):
    def convert(self, from_currency, to_currency, amount) -> float:
        pass

class FXConverter(CurrencyConverter):
    def convert(self, from_currency, to_currency, amount) -> float:
        print('Converting currency using FX API')
        print(f'{amount} {from_currency} = {amount * 1.2} {to_currency}')
        return amount * 1.15

class AlphaConverter(CurrencyConverter):
    def convert(self, from_currency, to_currency, amount) -> float:
        print('Converting currency using Alpha API')
        print(f'{amount} {from_currency} = {amount * 1.2} {to_currency}')
        return amount * 1.2

class App:
    def __init__(self, converter: CurrencyConverter):
        self.converter = converter

    def start(self):
        self.converter.convert('EUR', 'USD', 100)


if __name__ == '__main__':
    converter = AlphaConverter()
    app = App(converter)
    app.start()
# output    
# Converting currency using Alpha API
# 100 EUR = 120.0 USD

Source: pythontutorial.net

Similar codes

1 vote182 views1 answer
How to remove numbers from string in python pandas
Python
1 vote177 views1 answer
Python index where true
Python
0 vote190 views1 answer
Import external script in django views
Python Django
1 vote184 views1 answer
Check if the user is logged in django decorator
Python
7 votes182 views2 answers
How to create a variablein python
Python
0 vote169 views1 answer
Python datetime now only hour and minute
Python
0 vote171 views1 answer
Networkx largest component
Python
6 votes169 views1 answer
Install pip on windows 10 python 3.9
Python
0 vote158 views1 answer
Extract n grams from text python
Python
0 vote148 views2 answers
Iterate through a list and print from index x to y using for loop python
Python