gpascale/currencyconverter

A Python currency converter using the European Central Bank data.

Currency converter

This is a currency converter that uses historical rates against a reference currency (Euro).

Currency sources

The default source is the European Central Bank. This is the ECB historical rates for 42 currencies against the Euro since 1999. It can be downloaded here: eurofxref-hist.zip. The converter can use different sources as long as the format is the same.

Installation

You can install directly after cloning:

$ python setup.py install --user

Or use the Python package:

$ pip install --user currencyconverter

Launch the tests with tox:

$ tox

Command line example

$ python currency_converter.py 100 EUR --to USD
"100 EUR" is "137.59 USD" on 2014-03-28.

After installation, you should have currency_converter in your $PATH:

$ currency_converter 100 USD -d 2013-12-12

Python API example

Example:

>>> from currency_converter import CurrencyConverter
>>> c = CurrencyConverter()

Convert from EUR to USD:

>>> c.convert(100, 'EUR', 'USD') # doctest: +SKIP
137.5...

Default target currency is EUR:

>>> c.convert(100, 'EUR')
100.0
>>> c.convert(100, 'USD') # doctest: +SKIP
72.67...

Change reference date for rate:

>>> from datetime import datetime
>>> c.convert(100, 'EUR', 'USD', date=datetime(2013, 3, 21))
129.1...

Get a rate:

>>> c.get_rate('USD') # doctest: +SKIP
1.375...

Fallback mode on not supported dates:

>>> c = CurrencyConverter(fallback_on_wrong_date=True, verbose=True)
>>> c.convert(100, 'EUR', 'USD', date=datetime(1986, 2, 2))
/!\ Invalid date (currency was EUR), fallback to 1999-01-04
/!\ Invalid date (currency was USD), fallback to 1999-01-04
117.89...

Sometimes rates are missing:

>>> c.convert(100, 'BGN', date=datetime(1999, 11, 10))
Traceback (most recent call last):
RateNotFoundError: Currency BGN has no rate for date 1999-11-10.

But we also have a fallback mode for those:

>>> c = CurrencyConverter(fallback_on_wrong_date=True,
...                       fallback_on_missing_rate=True,
...                       verbose=True)
>>> c.convert(100, 'BGN', date=datetime(1999, 11, 10))
/!\ Missing rate for BGN, fallback to 2000-07-19
51.36...
>>> c.convert(100, 'BGN', 'EUR', date=datetime(1980, 1, 1))
/!\ Invalid date (currency was BGN), fallback to 1999-01-04
/!\ Missing rate for BGN, fallback to 2000-07-19
/!\ Invalid date (currency was EUR), fallback to 1999-01-04
51.36...

Other public members:

>>> c.last_date # doctest: +SKIP
datetime.datetime(2016, 4, 14, 0, 0)
>>> min(c.dates)
datetime.datetime(1999, 1, 4, 0, 0)
>>> sorted(c.currencies)
['AUD', 'BGN', 'BRL', 'CAD', 'CHF', 'CNY', 'CYP', 'CZK', 'DKK', ...

Error cases:

>>> c = CurrencyConverter()
>>> c.get_rate('BGN', date=datetime(1999, 11, 10)) # None, rate is missing
>>> c.get_rate('AAA')
Traceback (most recent call last):
ValueError: Currency AAA not supported.