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 vote180 views1 answer
Django manger
Python Django
0 vote121 views1 answer
How to find how many processors you have with python
Python
15 votes1.3K views4 answers
Web server python
Python
0 vote133 views1 answer
Requests.packages.urllib3.util.retry could not be resolved from source
Python
65 votes124 views6 answers
Python venv
Python
0 vote181 views1 answer
Sendgrid django smtp
Python Django
2 votes156 views1 answer
Open firefox python
Python
4 votes87 views1 answer
Pandas display one row
Python
1 vote139 views1 answer
Python sftp put file
Python
0 vote163 views1 answer
Jupyter notebook for pdf generation
Python