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| -rw-r--r-- | Doc/library/string.rst | 43 |
1 files changed, 31 insertions, 12 deletions
diff --git a/Doc/library/string.rst b/Doc/library/string.rst index 91f43e9..5542e9b 100644 --- a/Doc/library/string.rst +++ b/Doc/library/string.rst @@ -384,10 +384,10 @@ following: The ``'#'`` option causes the "alternate form" to be used for the conversion. The alternate form is defined differently for different -types. This option is only valid for integer, float, complex and -Decimal types. For integers, when binary, octal, or hexadecimal output +types. This option is only valid for integer, float and complex +types. For integers, when binary, octal, or hexadecimal output is used, this option adds the prefix respective ``'0b'``, ``'0o'``, or -``'0x'`` to the output value. For floats, complex and Decimal the +``'0x'`` to the output value. For float and complex the alternate form causes the result of the conversion to always contain a decimal-point character, even if no digits follow it. Normally, a decimal-point character appears in the result of these conversions @@ -476,20 +476,36 @@ with the floating point presentation types listed below (except ``'n'`` and ``None``). When doing so, :func:`float` is used to convert the integer to a floating point number before formatting. -The available presentation types for floating point and decimal values are: +The available presentation types for :class:`float` and +:class:`~decimal.Decimal` values are: +---------+----------------------------------------------------------+ | Type | Meaning | +=========+==========================================================+ - | ``'e'`` | Exponent notation. Prints the number in scientific | - | | notation using the letter 'e' to indicate the exponent. | - | | The default precision is ``6``. | + | ``'e'`` | Scientific notation. For a given precision ``p``, | + | | formats the number in scientific notation with the | + | | letter 'e' separating the coefficient from the exponent. | + | | The coefficient has one digit before and ``p`` digits | + | | after the decimal point, for a total of ``p + 1`` | + | | significant digits. With no precision given, uses a | + | | precision of ``6`` digits after the decimal point for | + | | :class:`float`, and shows all coefficient digits | + | | for :class:`~decimal.Decimal`. If no digits follow the | + | | decimal point, the decimal point is also removed unless | + | | the ``#`` option is used. | +---------+----------------------------------------------------------+ - | ``'E'`` | Exponent notation. Same as ``'e'`` except it uses an | - | | upper case 'E' as the separator character. | + | ``'E'`` | Scientific notation. Same as ``'e'`` except it uses | + | | an upper case 'E' as the separator character. | +---------+----------------------------------------------------------+ - | ``'f'`` | Fixed-point notation. Displays the number as a | - | | fixed-point number. The default precision is ``6``. | + | ``'f'`` | Fixed-point notation. For a given precision ``p``, | + | | formats the number as a decimal number with exactly | + | | ``p`` digits following the decimal point. With no | + | | precision given, uses a precision of ``6`` digits after | + | | the decimal point for :class:`float`, and uses a | + | | precision large enough to show all coefficient digits | + | | for :class:`~decimal.Decimal`. If no digits follow the | + | | decimal point, the decimal point is also removed unless | + | | the ``#`` option is used. | +---------+----------------------------------------------------------+ | ``'F'`` | Fixed-point notation. Same as ``'f'``, but converts | | | ``nan`` to ``NAN`` and ``inf`` to ``INF``. | @@ -518,7 +534,10 @@ The available presentation types for floating point and decimal values are: | | the precision. | | | | | | A precision of ``0`` is treated as equivalent to a | - | | precision of ``1``. The default precision is ``6``. | + | | precision of ``1``. With no precision given, uses a | + | | precision of ``6`` significant digits for | + | | :class:`float`, and shows all coefficient digits | + | | for :class:`~decimal.Decimal`. | +---------+----------------------------------------------------------+ | ``'G'`` | General format. Same as ``'g'`` except switches to | | | ``'E'`` if the number gets too large. The | |