price-parser 0.3.0

Extract price and currency from a raw string

price-parser is a small library for extracting price and currency from raw text strings.

Features:

• robust price amount and currency symbol extraction

• zero-effort handling of thousand and decimal separators

The main use case is parsing prices extracted from web pages. For example, you can write a CSS/XPath selector which targets an element with a price, and then use this library for cleaning it up, instead of writing custom site-specific regex or Python code.

License is BSD 3-clause.

Installation

pip install price-parser

price-parser requires Python 3.6+.

Usage

Basic usage

>>> from price_parser import Price
>>> price = Price.fromstring("22,90 €")
>>> price
Price(amount=Decimal('22.90'), currency='€')
>>> price.amount       # numeric price amount
Decimal('22.90')
>>> price.currency     # currency symbol, as appears in the string
'€'
>>> price.amount_text  # price amount, as appears in the string
'22,90'
>>> price.amount_float # price amount as float, not Decimal
22.9

If you prefer, Price.fromstring has an alias price_parser.parse_price, they do the same:

>>> from price_parser import parse_price
>>> parse_price("22,90 €")
Price(amount=Decimal('22.90'), currency='€')

The library has extensive tests (900+ real-world examples of price strings). Some of the supported cases are described below.

Supported cases

Unclean price strings with various currencies are supported; thousand separators and decimal separators are handled:

>>> Price.fromstring("Price: $119.00")
Price(amount=Decimal('119.00'), currency='$')

>>> Price.fromstring("15 130 Р")
Price(amount=Decimal('15130'), currency='Р')

>>> Price.fromstring("151,200 تومان")
Price(amount=Decimal('151200'), currency='تومان')

>>> Price.fromstring("Rp 1.550.000")
Price(amount=Decimal('1550000'), currency='Rp')

>>> Price.fromstring("Běžná cena 75 990,00 Kč")
Price(amount=Decimal('75990.00'), currency='Kč')

Euro sign is used as a decimal separator in a wild:

>>> Price.fromstring("1,235€ 99")
Price(amount=Decimal('1235.99'), currency='€')

>>> Price.fromstring("99 € 95 €")
Price(amount=Decimal('99'), currency='€')

>>> Price.fromstring("35€ 999")
Price(amount=Decimal('35'), currency='€')

Some special cases are handled:

>>> Price.fromstring("Free")
Price(amount=Decimal('0'), currency=None)

When price or currency can’t be extracted, corresponding attribute values are set to None:

>>> Price.fromstring("")
Price(amount=None, currency=None)

>>> Price.fromstring("Foo")
Price(amount=None, currency=None)

>>> Price.fromstring("50% OFF")
Price(amount=None, currency=None)

>>> Price.fromstring("50")
Price(amount=Decimal('50'), currency=None)

>>> Price.fromstring("R$")
Price(amount=None, currency='R$')

Currency hints

currency_hint argument allows to pass a text string which may (or may not) contain currency information. This feature is most useful for automated price extraction.

>>> Price.fromstring("34.99", currency_hint="руб. (шт)")
Price(amount=Decimal('34.99'), currency='руб.')

Note that currency mentioned in the main price string may be preferred over currency specified in currency_hint argument; it depends on currency symbols found there. If you know the correct currency, you can set it directly:

>>> price = Price.fromstring("1 000")
>>> price.currency = 'EUR'
>>> price
Price(amount=Decimal('1000'), currency='EUR')

Decimal separator

If you know which symbol is used as a decimal separator in the input string, pass that symbol in the decimal_separator argument to prevent price-parser from guessing the wrong decimal separator symbol.

>>> Price.fromstring("Price: $140.600", decimal_separator=".")
Price(amount=Decimal('140.600'), currency='$')

>>> Price.fromstring("Price: $140.600", decimal_separator=",")
Price(amount=Decimal('140600'), currency='$')

Contributing

• Source code: https://github.com/scrapinghub/price-parser

• Issue tracker: https://github.com/scrapinghub/price-parser/issues

Use tox to run tests with different Python versions:

tox

The command above also runs type checks; we use mypy.

Changes

0.3.0 (2019-10-19)

• New Price.fromstring argument decimal_separator allows to override decimal separator for the cases where it is known (i.e. disable decimal separator detection);

• NTD and RBM unofficial currency names are added;

• quantifiers in regular expressions are made non-greedy, which provides a small speedup;

• test improvements.

0.2.4 (2019-07-03)

• Declare price-parser as providing type annotations (pep-561). This enables better type checking for projects using price-parser.

• improved test coverage

0.2.3 (2019-06-18)

• Folow-up for 0.2.2 release: improved parsing of prices with 4+ digits after a decimal separator.

0.2.2 (2019-06-18)

• Fixed parsing of prices with 4+ digits after a decimal separator.

0.2.1 (2019-04-19)

• 23 additional currency symbols are added;

• A$ alias for Australian Dollar is added.

0.2 (2019-04-12)

Added support for currencies replaced by euro.

0.1.1 (2019-04-12)

Minor packaging fixes.

0.1 (2019-04-12)

Initial release.