Currency-converter

Currency converter based on fixer.io

This repository contains 2 applications:

• Command line interface: currency_converter.py
  • convert amounts using command line arguments
• Flask API - site.py
  • convert amounts using URIs

Both of these apps are using the CurrencyConverter class from converter_class.py.

• It uses fixer.io in the background to retrieve the actual conversion rates.
• The application has been developed using the TDD methodology
• Conversion rates are backed up in a pickle file, so the program can work without internet connection (but the conversion rates can be obsolete)
• The program checks if newer conversion rates are available from fixer.io, if yes downloads them and stores into pickle.

Code

For more information about how the code works, check the docstrings in the code (mainly converter_class.py).

All the code has been revised with pylint

Testing

To run the tests use py.test

There are two tests:

• test_converter_class.py tests for converter_class.py
• test_site.py tests for the flask app

Example output:

Try to run the following code:

pytest test_converter_class.py

Usage example

• There are three parameters in both applications:
  • amount - amount which we want to convert - float
  • input_currency - input currency - 3 letters name or currency symbol
  • output_currency - requested/output currency - 3 letters name or currency symbol. If output currency is omitted, the amount is converted to every possible currency (currencies available from fixer.io).

Note: There are symbols which represent more than one currency. E.g. $ can be USD, AUD, etc. If you provide this type of symbol as input_currency an error will be raised. If you use this type of symbol as output, the amount is converted to every possible currency represented by that symbol.

CLI app

• For listing the parameters, try: python currency_converter.py -h

Currency converter CLI

optional arguments:
  -h, --help            show this help message and exit
  --amount RAW_INPUT_AMOUNT
                        Input amount to be converted
  --input_currency RAW_INPUT_CURRENCY
                        Input currency. 2 options: 3-letter currency code;
                        currency symbol
  --output_currency RAW_OUTPUT_CURRENCY
                        Output currency. 2 options: 3-letter currency code;
                        currency_symbol. Optional parameter, if omitted, all
                        available currencies will be used

Examples:

python currency_converter.py --amount 100.0 --input_currency EUR --output_currency CZK

{   
    "input": {
        "amount": 100.0,
        "currency": "EUR"
    },
    "output": {
        "CZK": 2563.6, 
    }
}

---

python currency_converter.py --amount 100.0 --input_currency EUR

{
    "input": {
        "amount": 100.0,
        "currency": "EUR"
    },
    "output": {
        "AUD": 155.65,
        "BGN": 195.58,
        "BRL": 381.93,
        "CAD": 149.63,
        "CHF": 116.78,
        "CNY": 781.69,
        "CZK": 2563.6,
        "DKK": 744.21,
        "GBP": 88.33,
        "HKD": 923.23,
        "HRK": 754.63,
        "HUF": 31445.0,
        "IDR": 1600700.0,
        "ILS": 415.19,
        "INR": 7624.3,
        "JPY": 13252.0,
        "KRW": 129150.0,
        "MXN": 2220.3,
        "MYR": 481.6,
        "NOK": 975.75,
        "NZD": 171.41,
        "PHP": 5989.1,
        "PLN": 421.42,
        "RON": 463.2,
        "RUB": 6979.1,
        "SEK": 992.65,
        "SGD": 159.25,
        "THB": 3855.9,
        "TRY": 454.89,
        "USD": 118.17,
        "ZAR": 1598.5
    }
}

API

Run python site.py

Open the browser, and you try to run the following uris:

http://localhost:5000/currency_converter?amount=10&input_currency=EUR&output_currency=$

{
  "input": {
    "amount": 10.0, 
    "currency": "EUR"
  }, 
  "output": {
    "AUD": 15.56, 
    "CAD": 14.96, 
    "HKD": 92.32, 
    "MXN": 222.03, 
    "NZD": 17.14, 
    "SGD": 15.93, 
    "USD": 11.82
  }
}

---

http://localhost:5000/currency_converter?amount=money&input_currency=EUR&output_currency=$

{
  "input": {
    "amount": "money", 
    "currency": "EUR"
  }, 
  "output": {
    "error": "Conversion error, check the input parameters"
  }
}

The last example shows an example of an error

Installation

These were developed using the Anaconda distribution. The enviroment is exported to currency35.yml

To create the same environment, use:

conda env create -f currency35.yml

If you are using a different distribution use requirements.txt (use with virtualenv)

More info to be added later

Development setup

To be added later

TODO

Code documentation

Release History

• 0.0.1
  • Work in progress

Meta

Gabor Patassy – patex1987@gmail.com

https://github.com/patex1987

Contributing

To be added later