/Doc/library/fpformat.rst

 1
 2:mod:`fpformat` --- Floating point conversions
 3==============================================
 4
 5.. module:: fpformat
 6   :synopsis: General floating point formatting functions.
 7   :deprecated:
 8
 9.. deprecated:: 2.6
10    The :mod:`fpformat` module has been removed in Python 3.0.
11
12.. sectionauthor:: Moshe Zadka <moshez@zadka.site.co.il>
13
14
15The :mod:`fpformat` module defines functions for dealing with floating point
16numbers representations in 100% pure Python.
17
18.. note::
19
20   This module is unnecessary: everything here can be done using the ``%`` string
21   interpolation operator described in the :ref:`string-formatting` section.
22
23The :mod:`fpformat` module defines the following functions and an exception:
24
25
26.. function:: fix(x, digs)
27
28   Format *x* as ``[-]ddd.ddd`` with *digs* digits after the point and at least one
29   digit before. If ``digs <= 0``, the decimal point is suppressed.
30
31   *x* can be either a number or a string that looks like one. *digs* is an
32   integer.
33
34   Return value is a string.
35
36
37.. function:: sci(x, digs)
38
39   Format *x* as ``[-]d.dddE[+-]ddd`` with *digs* digits after the  point and
40   exactly one digit before. If ``digs <= 0``, one digit is kept and the point is
41   suppressed.
42
43   *x* can be either a real number, or a string that looks like one. *digs* is an
44   integer.
45
46   Return value is a string.
47
48
49.. exception:: NotANumber
50
51   Exception raised when a string passed to :func:`fix` or :func:`sci` as the *x*
52   parameter does not look like a number. This is a subclass of :exc:`ValueError`
53   when the standard exceptions are strings.  The exception value is the improperly
54   formatted string that caused the exception to be raised.
55
56Example::
57
58   >>> import fpformat
59   >>> fpformat.fix(1.23, 1)
60   '1.2'
61