diff options
author | Raymond Hettinger <python@rcn.com> | 2008-02-14 11:57:25 (GMT) |
---|---|---|
committer | Raymond Hettinger <python@rcn.com> | 2008-02-14 11:57:25 (GMT) |
commit | d68bf02810b76db382004acb2f60a0515381feec (patch) | |
tree | 3ac01802e64e11f7449774efd8667ce498b820e0 /Doc | |
parent | 27a90d989db3b6e748ccf08556464a6b830c19f0 (diff) | |
download | cpython-d68bf02810b76db382004acb2f60a0515381feec.zip cpython-d68bf02810b76db382004acb2f60a0515381feec.tar.gz cpython-d68bf02810b76db382004acb2f60a0515381feec.tar.bz2 |
Show how to remove exponents.
Diffstat (limited to 'Doc')
-rw-r--r-- | Doc/library/decimal.rst | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/Doc/library/decimal.rst b/Doc/library/decimal.rst index 2f191bd..0a8262d 100644 --- a/Doc/library/decimal.rst +++ b/Doc/library/decimal.rst @@ -1590,6 +1590,7 @@ to handle the :meth:`quantize` step:: ... return (x * y).quantize(fp) >>> def div(x, y, fp=TWOPLACES): ... return (x / y).quantize(fp) + >>> mul(a, b) # Automatically preserve fixed-point Decimal('325.62') >>> div(b, a) @@ -1615,6 +1616,16 @@ of significant places in the coefficient. For example, expressing :const:`5.0E+3` as :const:`5000` keeps the value constant but cannot show the original's two-place significance. +If an application does not care about tracking significance, it is easy to +remove the exponent and trailing zeroes, losing signficance, but keeping the +value unchanged:: + + >>> def remove_exponent(d): + ... return d.quantize(Decimal(1)) if d == d.to_integral() else d.normalize() + + >>> remove_exponent(Decimal('5E+3')) + Decimal('5000') + Q. Is there a way to convert a regular float to a :class:`Decimal`? A. Yes, all binary floating point numbers can be exactly expressed as a |