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Code Issues Releases Wiki Activity

Issue #7051: Clarify behaviour of 'g' and 'G'-style formatting.

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Mark Dickinson 2009-10-08 20:02:25 +00:00
parent 539bff4234
commit d5a713ec30
1 changed files with 25 additions and 7 deletions
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Doc/library/string.rst
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@ -446,15 +446,33 @@ The available presentation types for floating point and decimal values are:
+---------+----------------------------------------------------------+
| ``'F'`` | Fixed point. Same as ``'f'``. |
+---------+----------------------------------------------------------+
| ``'g'`` | General format. This prints the number as a fixed-point |
| | number, unless the number is too large, in which case |
| | it switches to ``'e'`` exponent notation. Infinity and |
| | NaN values are formatted as ``inf``, ``-inf`` and |
| | ``nan``, respectively. |
| ``'g'`` | General format. For a given precision ``p >= 1``, |
| | this rounds the number to ``p`` significant digits and |
| | then formats the result in either fixed-point format |
| | or in scientific notation, depending on its magnitude. |
| | |
| | The precise rules are as follows: suppose that the |
| | result formatted with presentation type ``'e'`` and |
| | precision ``p-1`` would have exponent ``exp``. Then |
| | if ``-4 <= exp < p``, the number is formatted |
| | with presentation type ``'f'`` and precision |
| | ``p-1-exp``. Otherwise, the number is formatted |
| | with presentation type ``'e'`` and precision ``p-1``. |
| | In both cases insignificant trailing zeros are removed |
| | from the significand, and the decimal point is also |
| | removed if there are no remaining digits following it. |
| | |
| | Postive and negative infinity, positive and negative |
| | zero, and nans, are formatted as ``inf``, ``-inf``, |
| | ``0``, ``-0`` and ``nan`` respectively, regardless of |
| | the precision. |
| | |
| | A precision of ``0`` is treated as equivalent to a |
| | precision of ``1``. |
+---------+----------------------------------------------------------+
| ``'G'`` | General format. Same as ``'g'`` except switches to |
| | ``'E'`` if the number gets to large. The representations |
| | of infinity and NaN are uppercased, too. |
| | ``'E'`` if the number gets too large. The |
| | representations of infinity and NaN are uppercased, too. |
+---------+----------------------------------------------------------+
| ``'n'`` | Number. This is the same as ``'g'``, except that it uses |
| | the current locale setting to insert the appropriate |