Number Formatting

Contents

1 Pattern Syntax
2 Parsing Numbers

Support for locale-specific formatting and parsing of numbers is provided by the babel.numbers module:

System Message: ERROR/3 (doc/numbers.txt, line 16)

Unknown directive type "code-block".

.. code-block:: pycon

    >>> from babel.numbers import format_number, format_decimal, format_percent

Examples:

System Message: ERROR/3 (doc/numbers.txt, line 22)

Unknown directive type "code-block".

.. code-block:: pycon

    >>> format_decimal(1.2345, locale='en_US')
    u'1.234'
    >>> format_decimal(1.2345, locale='sv_SE')
    u'1,234'
    >>> format_decimal(12345, locale='de_DE')
    u'12.345'

1 Pattern Syntax

While Babel makes it simple to use the appropriate number format for a given locale, you can also force it to use custom patterns. As with date/time formatting patterns, the patterns Babel supports for number formatting are based on the Locale Data Markup Language specification (LDML).

Examples:

System Message: ERROR/3 (doc/numbers.txt, line 42)

Unknown directive type "code-block".

.. code-block:: pycon

    >>> format_decimal(-1.2345, format='#,##0.##;-#', locale='en')
    u'-1.23'
    >>> format_decimal(-1.2345, format='#,##0.##;(#)', locale='en')
    u'(1.23)'

The syntax for custom number format patterns is described in detail in the the specification. The following table is just a relatively brief overview.

Symbol Description

0 Digit

1-9 '1' through '9' indicate rounding.

@ Significant digit

# Digit, zero shows as absent

. Decimal separator or monetary decimal separator

- Minus sign

, Grouping separator

E Separates mantissa and exponent in scientific notation

+ Prefix positive exponents with localized plus sign

; Separates positive and negative subpatterns

% Multiply by 100 and show as percentage

‰ Multiply by 1000 and show as per mille

¤ Currency sign, replaced by currency symbol. If doubled, replaced by international currency symbol. If tripled, uses the long form of the decimal symbol.

' Used to quote special characters in a prefix or suffix

* Pad escape, precedes pad character

Symbol	Description
`0`	Digit
`1-9`	'1' through '9' indicate rounding.
`@`	Significant digit
`#`	Digit, zero shows as absent
`.`	Decimal separator or monetary decimal separator
`-`	Minus sign
`,`	Grouping separator
`E`	Separates mantissa and exponent in scientific notation
`+`	Prefix positive exponents with localized plus sign
`;`	Separates positive and negative subpatterns
`%`	Multiply by 100 and show as percentage
`‰`	Multiply by 1000 and show as per mille
`¤`	Currency sign, replaced by currency symbol. If doubled, replaced by international currency symbol. If tripled, uses the long form of the decimal symbol.
`'`	Used to quote special characters in a prefix or suffix
`*`	Pad escape, precedes pad character

2 Parsing Numbers

Babel can also parse numeric data in a locale-sensitive manner:

System Message: ERROR/3 (doc/numbers.txt, line 96)

Unknown directive type "code-block".

.. code-block:: pycon

    >>> from babel.numbers import parse_decimal, parse_number

Examples:

System Message: ERROR/3 (doc/numbers.txt, line 102)

Unknown directive type "code-block".

.. code-block:: pycon

    >>> parse_decimal('1,099.98', locale='en_US')
    1099.98
    >>> parse_decimal('1.099,98', locale='de')
    1099.98
    >>> parse_decimal('2,109,998', locale='de')
    Traceback (most recent call last):
      ...
    NumberFormatError: '2,109,998' is not a valid decimal number

Note

Number parsing is not properly implemented yet