Currency Converter

A Python currency converter using the European Central Bank data.

Project maintained by alexprengere Hosted on GitHub Pages — Theme by mattgraham

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

Currency data 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: The converter can use different sources as long as the format is the same.


You can install directly after cloning:

$ python install --user

Or use the Python package:

$ pip install --user currencyconverter

Command line tool

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

$ currency_converter 100 USD --to EUR
"100.000 USD" is "87.881 EUR" on 2016-04-20

Python API

Create once the currency converter object:

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

Convert from EUR to USD using the last available rate:

>>> c.convert(100, 'EUR', 'USD')

Default target currency is EUR:

>>> c.convert(100, 'EUR')
>>> c.convert(100, 'USD')

You can change the date of the rate:

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


Some rates are missing:

>>> c.convert(100, 'BGN', date=date(2010, 11, 21))
Traceback (most recent call last):
RateNotFoundError: BGN has no rate for '2010-11-21'

But we have a fallback mode for those, using a linear interpolation of the closest known rates, as long as you ask for a date within the currency date bounds:

>>> c = CurrencyConverter(fallback_on_missing_rate=True)
>>> c.convert(100, 'BGN', date=date(2010, 11, 21))

We also have a fallback mode for dates outside the currency bounds:

>>> c = CurrencyConverter()
>>> c.convert(100, 'EUR', 'USD', date=date(1986, 2, 2))
Traceback (most recent call last):
RateNotFoundError: '1986-02-02' not in USD bounds '1999-01-04/2016-04-20'
>>> c = CurrencyConverter(fallback_on_wrong_date=True)
>>> c.convert(100, 'EUR', 'USD', date=date(1986, 2, 2)) # fallback to 1999-01-04

Other attributes

>>> first_date, last_date = c.bounds['USD']
>>> first_date, 1, 4)
>>> last_date, 11, 1)
>>> c.currencies
set(['SGD', 'CAD', 'SEK', 'GBP', ...
>>> 'AAA' in c.currencies
>>> c.convert(100, 'AAA')
Traceback (most recent call last):
ValueError: AAA is not a supported currency

Finally, you can use your own currency file, as long as it has the same format (ECB):

# Load the packaged data (might not be up to date)
c = CurrencyConverter()

# Load the up to date full history
c = CurrencyConverter('')

# Load only the latest rates (single day data source)
c = CurrencyConverter('')

# Load your custom file
c = CurrencyConverter('./path/to/currency/file.csv')