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 vote126 views2 answers
Read image from a folder python
Python
0 vote125 views3 answers
While
Python
12 votes125 views2 answers
Python sort array of dictionary by value
Python
2 votes130 views2 answers
Replace nan numpy array
Python
0 vote108 views2 answers
How plot graph by using group by function in python
Python
0 vote140 views1 answer
The Python 2 bindings for rpm are needed for this module. If you require Python 3 support use the `dnf` Ansible module instead.. The Python 2 yum module is needed for this module. If you require Python 3 support use the `dnf` Ansible module instead.
Python
7 votes120 views3 answers
Python lowercase first letter
Python
0 vote121 views1 answer
Open pkl file python
Python
0 vote153 views3 answers
Pyinstaller add files
Python
0 vote148 views1 answer
Create django model field based on another field
Python Django