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

0 vote273 views1 answer
Djanog admin cookbook change text
Python
1 vote231 views1 answer
Numpy random float array between 0 and 1
Python
10 votes256 views4 answers
File path current directory python
Python
0 vote260 views2 answers
Identity matrix with numpy
Python
0 vote246 views1 answer
Os get directory from string
Python
35 votes250 views6 answers
How to create an array in python
Python
0 vote257 views1 answer
Parce que in english
Python
68 votes230 views5 answers
Pandas iterate rows
Python
0 vote272 views2 answers
Fatal error: Python.h: No such file or directory 45 | #include <Python.h> | ^~~~~~~~~~ compilation terminated. error: command 'gcc' failed with exit status 1
Python
12 votes236 views1 answer
Make a zero list python
Python