| msg123603 - (view) |
Author: Stefan Krah (skrah) *  |
Date: 2010-12-08 13:56 |
| I'm not sure if this is a documentation issue or a bug. If watchexp=0, quantize() also allows any number of digits: >>> x = Decimal("6885998238912213556789006667970467609814") >>> y = Decimal("1e2") >>> x.quantize(y) Traceback (most recent call last): File "", line 1, in File "/usr/local/lib/python3.2/decimal.py", line 2488, in quantize 'quantize result has too many digits for current context') File "/usr/local/lib/python3.2/decimal.py", line 3925, in _raise_error raise error(explanation) decimal.InvalidOperation: quantize result has too many digits for current context >>> >>> x.quantize(y, watchexp=0) Decimal('6.8859982389122135567890066679704676098E+39') |
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| msg123607 - (view) |
Author: Stefan Krah (skrah) * |
Date: 2010-12-08 14:36 |
| NaNs, however, are decapitated: >>> x = Decimal("NaN5357671565858315212612021522416387828577") >>> y = 0 >>> x.quantize(y, watchexp=0) Decimal('NaN8315212612021522416387828577') |
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| msg164429 - (view) |
Author: Stefan Krah (skrah) * |
Date: 2012-06-30 21:56 |
| Ping. We have to decide if we need watchexp in _decimal. I've left it out so far since all I can gather from the docs is that it somehow behaves like _rescale. Can we deprecate it and replace it by a proper rescale? |
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| msg164430 - (view) |
Author: Mark Dickinson (mark.dickinson) * |
Date: 2012-06-30 22:03 |
| I'd be happy to see watchexp deprecated. It feels like a leftover implementation artefact; its behaviour isn't properly defined anywhere, and as far as I can tell it has only a single testcase. |
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| msg164439 - (view) |
Author: Raymond Hettinger (rhettinger) * |
Date: 2012-07-01 00:40 |
| Does anyone know why watchexp was put there in the first place? http://speleotrove.com/decimal/daops.html#refquant If no motivation for this can be found, I agree with Mark that it should be deprecated and removed. |
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| msg164467 - (view) |
Author: Stefan Krah (skrah) * |
Date: 2012-07-01 09:42 |
| watchexp was available in rescale() from the beginning ... http://svn.python.org/view/sandbox/trunk/decimal/Decimal.py?revision=40721&view=markup ... and rescale() was renamed to quantize() in http://svn.python.org/view/sandbox/trunk/decimal/Decimal.py?revision=40909&view=markup rescale() was once part of the specification, but had identical semantics to quantize(), which is not specified to allow unlimited rescaling. I suppose the original rescale() in the sandbox had watchexp for convenience, in order to avoid two separate functions. watchexp made it into quantize(), probably because people thought there is a need for unlimited rescaling. This may be true, but I'd really prefer to expose rescale() as the unlimited version then. While it's unusual to just drop an API without deprecation, I think it's OK in this instance: Virtually all decimal code I saw needs to be cleaned up anyway because it uses tons of underscore methods from decimal.py. The only thing that worries me is that there might be code which *really* needs unlimited rescaling. Such code could of course also use a temporary context. So I propose this: Deprecate watchexp and leave it in the Python version for one release. The C version won't have watchexp from the start. After all, PEP-399 allows accelerator modules to implement a subset of the functionality of the Python version -- sometimes PEPs are a wonderful thing :). |
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| msg169141 - (view) |
Author: Stefan Krah (skrah) * |
Date: 2012-08-25 15:14 |
| Here's a patch deprecating watchexp. |
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| msg169448 - (view) |
Author: Roundup Robot (python-dev)  |
Date: 2012-08-30 10:39 |
| New changeset 7db16ff9f5fd by Stefan Krah in branch 'default': Closes #10650: Deprecate the watchexp parameter of Decimal.quantize(). http://hg.python.org/cpython/rev/7db16ff9f5fd |
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| msg170085 - (view) |
Author: Roundup Robot (python-dev) |
Date: 2012-09-09 09:18 |
| New changeset e4ca4edee8bd by Stefan Krah in branch 'default': Closes #10650: Deprecate the watchexp parameter of Decimal.quantize(). http://hg.python.org/cpython/rev/e4ca4edee8bd |
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| msg217631 - (view) |
Author: Roundup Robot (python-dev) |
Date: 2014-04-30 17:16 |
| New changeset c2f827af02a2 by Stefan Krah in branch 'default': Issue #10650: Remove the non-standard 'watchexp' parameter from the http://hg.python.org/cpython/rev/c2f827af02a2 |
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