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# 7.11. `fpformat` — Floating point conversions

2.6 版后已移除: The `fpformat` module has been removed in Python 3.

The `fpformat` module defines functions for dealing with floating point numbers representations in 100% pure Python.

注解

This module is unnecessary: everything here can be done using the `%` string interpolation operator described in the String Formatting Operations section.

The `fpformat` module defines the following functions and an exception:

`fpformat.``fix`(x, digs)

  Format x as `[-]ddd.ddd` with digs digits after the point and at least one digit before. If `digs <= 0`, the decimal point is suppressed.

  x can be either a number or a string that looks like one. digs is an integer.

  Return value is a string.

`fpformat.``sci`(x, digs)

  Format x as `[-]d.dddE[+-]ddd` with digs digits after the point and exactly one digit before. If `digs <= 0`, one digit is kept and the point is suppressed.

  x can be either a real number, or a string that looks like one. digs is an integer.

  Return value is a string.

exception `fpformat.``NotANumber`

  Exception raised when a string passed to `fix()` or `sci()` as the x parameter does not look like a number. This is a subclass of `ValueError` when the standard exceptions are strings. The exception value is the improperly formatted string that caused the exception to be raised.

Example:

    >>> import fpformat
    >>> fpformat.fix(1.23, 1)
    '1.2'