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| author | Martin Panter <vadmium+py@gmail.com> | 2016-02-13 00:41:37 +0000 |
|---|---|---|
| committer | Martin Panter <vadmium+py@gmail.com> | 2016-02-13 00:41:37 +0000 |
| commit | bc1ee460dcbe5811ebb10a6cacd8d3670846f039 (patch) | |
| tree | 1ce59d900fa4173482085eeca44bfe864336534a /Doc/library/string.rst | |
| parent | e0b23095ee03a11d09f38cbc689307dc5c93afda (diff) | |
| download | cpython-git-bc1ee460dcbe5811ebb10a6cacd8d3670846f039.tar.gz | |
Issue #25179: Documentation for formatted string literals aka f-strings
Some of the inspiration and wording is taken from the text of PEP 498 by Eric
V. Smith, and the existing str.format() documentation.
Diffstat (limited to 'Doc/library/string.rst')
| -rw-r--r-- | Doc/library/string.rst | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/Doc/library/string.rst b/Doc/library/string.rst index 5b917d939b..cda8e8682f 100644 --- a/Doc/library/string.rst +++ b/Doc/library/string.rst @@ -188,7 +188,9 @@ Format String Syntax The :meth:`str.format` method and the :class:`Formatter` class share the same syntax for format strings (although in the case of :class:`Formatter`, -subclasses can define their own format string syntax). +subclasses can define their own format string syntax). The syntax is +related to that of :ref:`formatted string literals <f-strings>`, but +there are differences. Format strings contain "replacement fields" surrounded by curly braces ``{}``. Anything that is not contained in braces is considered literal text, which is @@ -283,7 +285,8 @@ Format Specification Mini-Language "Format specifications" are used within replacement fields contained within a format string to define how individual values are presented (see -:ref:`formatstrings`). They can also be passed directly to the built-in +:ref:`formatstrings` and :ref:`f-strings`). +They can also be passed directly to the built-in :func:`format` function. Each formattable type may define how the format specification is to be interpreted. @@ -308,7 +311,8 @@ The general form of a *standard format specifier* is: If a valid *align* value is specified, it can be preceded by a *fill* character that can be any character and defaults to a space if omitted. It is not possible to use a literal curly brace ("``{``" or "``}``") as -the *fill* character when using the :meth:`str.format` +the *fill* character in a :ref:`formatted string literal +<f-strings>` or when using the :meth:`str.format` method. However, it is possible to insert a curly brace with a nested replacement field. This limitation doesn't affect the :func:`format` function. |