Mailman 3 July 2005 - Python-checkins

python/dist/src/Doc/lib libsets.tex,1.17,1.18
by rhettinger＠users.sourceforge.net July 1, 2005

July 1, 2005

Update of /cvsroot/python/python/dist/src/Doc/lib In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv19854 Modified Files: libsets.tex Log Message: Provide a comparison to the builtin set types. Index: libsets.tex =================================================================== RCS file: /cvsroot/python/python/dist/src/Doc/lib/libsets.tex,v retrieving revision 1.17 retrieving revision 1.18 diff -u -d -r1.17 -r1.18 --- libsets.tex 10 Apr 2005 17:32:35 -0000 1.17 +++ libsets.tex 1 Jul 2005 23:00:13 -0000 1.18 @@ -133,7 +133,7 @@ but not found in \class{ImmutableSet}: \begin{tableiii}{c|c|l}{code}{Operation}{Equivalent}{Result} - \lineiii{\var{s}.union_update(\var{t})} + \lineiii{\var{s}.update(\var{t})} {\var{s} \textbar= \var{t}} {return set \var{s} with elements added from \var{t}} \lineiii{\var{s}.intersection_update(\var{t})} @@ -161,12 +161,17 @@ {remove all elements from set \var{s}} \end{tableiii} -Note, the non-operator versions of \method{union_update()}, +Note, the non-operator versions of \method{update()}, \method{intersection_update()}, \method{difference_update()}, and \method{symmetric_difference_update()} will accept any iterable as an argument. \versionchanged[Formerly all arguments were required to be sets]{2.3.1} +Also note, the module also includes a \method{union_update()} method +which is an alias for \method{update()}. The method is included for +backwards compatability. Programmers should prefer the +\method{update()} method because it the one supported by the builtin +\class{set()} and \class{frozenset()} types. \subsection{Example \label{set-example}} @@ -231,3 +236,28 @@ where one thread is updating a set while another has temporarily wrapped it in \class{_TemporarilyImmutableSet}. In other words, sets of mutable sets are not thread-safe. + + +\subsection{Comparison to the built-in \class{set} types + \label{comparison-to-builtin-set}} + +The built-in \class{set} and \class{frozenset} types were designed based +on lessons learned from the \module{sets} module. The key differences are: + +\begin{itemize} +\item \class{Set} and \class{ImmutableSet} were renamed to \class{set} and + \class{frozenset}. +\item There is no equivalent to \class{BaseSet}. Instead, use + \code{isinstance(x, (set, frozenset))}. +\item The hash algorithm for the built-ins performs significantly better + (fewer collisions) for most datasets. +\item The built-in versions have more space efficient pickles. +\item The built-in versions do not have a \method{union_update()} method. + Instead, use the \method{update()} method which is equivalent. +\item The built-in versions do not have a \method{_repr(sort=True)} method. + Instead, use the built-in \function{repr()} and \function{sorted()} + functions: \code{repr(sorted(s))}. +\item The built-in version does not have a protocol for automatic conversion + to immutable. Many found this feature to be confusing and no one + in the community reported having found real uses for it. +\end{itemize}

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python/dist/src/Tools/scripts texcheck.py, 1.12, 1.13
by rhettinger＠users.sourceforge.net July 1, 2005

July 1, 2005

Update of /cvsroot/python/python/dist/src/Tools/scripts In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv17417 Modified Files: texcheck.py Log Message: Teach texcheck about \textbar Index: texcheck.py =================================================================== RCS file: /cvsroot/python/python/dist/src/Tools/scripts/texcheck.py,v retrieving revision 1.12 retrieving revision 1.13 diff -u -d -r1.12 -r1.13 --- texcheck.py 12 Jul 2004 13:29:10 -0000 1.12 +++ texcheck.py 1 Jul 2005 22:55:43 -0000 1.13 @@ -57,6 +57,7 @@ \email \kwindex \refexmodindex \filenq \e \menuselection \exindex \linev \newsgroup \verbatim \setshortversion \author \authoraddress \paragraph \subparagraph \cmemberline + \textbar """ def matchclose(c_lineno, c_symbol, openers, pairmap):

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python/dist/src/Tools/bgen/bgen bgenGenerator.py, 1.20, 1.21 bgenType.py, 1.17, 1.18 bgenVariable.py, 1.8, 1.9
by jackjansen＠users.sourceforge.net July 1, 2005

July 1, 2005

Update of /cvsroot/python/python/dist/src/Tools/bgen/bgen In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv2066 Modified Files: bgenGenerator.py bgenType.py bgenVariable.py Log Message: Added methods mkvaluePreCheck and getargsPreCheck, which are called (for each variable) before calling Py_BuildValue and PyArg_Parse. Index: bgenGenerator.py =================================================================== RCS file: /cvsroot/python/python/dist/src/Tools/bgen/bgen/bgenGenerator.py,v retrieving revision 1.20 retrieving revision 1.21 diff -u -d -r1.20 -r1.21 --- bgenGenerator.py 30 Jun 2005 15:00:13 -0000 1.20 +++ bgenGenerator.py 1 Jul 2005 20:23:27 -0000 1.21 @@ -194,6 +194,7 @@ if arg.flags == SelfMode: continue if arg.mode in (InMode, InOutMode): + arg.getargsPreCheck() fmt = fmt + arg.getargsFormat() args = arg.getargsArgs() if args: @@ -242,6 +243,7 @@ if not arg: continue if arg.flags == ErrorMode: continue if arg.mode in (OutMode, InOutMode): + arg.mkvaluePreCheck() fmt = fmt + arg.mkvalueFormat() lst = lst + sep + arg.mkvalueArgs() if fmt == "": Index: bgenType.py =================================================================== RCS file: /cvsroot/python/python/dist/src/Tools/bgen/bgen/bgenType.py,v retrieving revision 1.17 retrieving revision 1.18 diff -u -d -r1.17 -r1.18 --- bgenType.py 28 Jun 2005 15:14:35 -0000 1.17 +++ bgenType.py 1 Jul 2005 20:23:27 -0000 1.18 @@ -61,11 +61,18 @@ """ return "&" + name + def getargsPreCheck(self, name): + """Perform any actions needed before calling getargs(). + + This could include declaring temporary variables and such. + """ + def getargsCheck(self, name): """Perform any needed post-[new]getargs() checks. This is type-dependent; the default does not check for errors. - An example would be a check for a maximum string length.""" + An example would be a check for a maximum string length, or it + could do post-getargs() copying or conversion.""" def passInput(self, name): """Return an argument for passing a variable into a call. @@ -119,6 +126,12 @@ """ return name + def mkvaluePreCheck(self, name): + """Perform any actions needed before calling mkvalue(). + + This could include declaring temporary variables and such. + """ + def cleanup(self, name): """Clean up if necessary. Index: bgenVariable.py =================================================================== RCS file: /cvsroot/python/python/dist/src/Tools/bgen/bgen/bgenVariable.py,v retrieving revision 1.8 retrieving revision 1.9 diff -u -d -r1.8 -r1.9 --- bgenVariable.py 28 Jun 2005 15:14:35 -0000 1.8 +++ bgenVariable.py 1 Jul 2005 20:23:27 -0000 1.9 @@ -63,6 +63,9 @@ def getargsCheck(self): return self.type.getargsCheck(self.name) + def getargsPreCheck(self): + return self.type.getargsPreCheck(self.name) + def passArgument(self): """Return the string required to pass the variable as argument. @@ -95,6 +98,9 @@ """Call the type's mkvalueArgs method.""" return self.type.mkvalueArgs(self.name) + def mkvaluePreCheck(self): + return self.type.mkvaluePreCheck(self.name) + def cleanup(self): """Call the type's cleanup method.""" return self.type.cleanup(self.name)

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python/dist/src/Doc/lib libdecimal.tex, 1.24.2.2, 1.24.2.3
by rhettinger＠users.sourceforge.net July 1, 2005

July 1, 2005

Update of /cvsroot/python/python/dist/src/Doc/lib In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv20564 Modified Files: Tag: release24-maint libdecimal.tex Log Message: More info on rounding modes. Add sections for floating point notes. Index: libdecimal.tex =================================================================== RCS file: /cvsroot/python/python/dist/src/Doc/lib/libdecimal.tex,v retrieving revision 1.24.2.2 retrieving revision 1.24.2.3 diff -u -d -r1.24.2.2 -r1.24.2.3 --- libdecimal.tex 15 Jun 2005 16:54:30 -0000 1.24.2.2 +++ libdecimal.tex 1 Jul 2005 16:56:53 -0000 1.24.2.3 @@ -501,13 +501,15 @@ arithmetic operations in the context. The \var{rounding} option is one of: - \constant{ROUND_CEILING} (towards \constant{Infinity}), - \constant{ROUND_DOWN} (towards zero), - \constant{ROUND_FLOOR} (towards \constant{-Infinity}), - \constant{ROUND_HALF_DOWN} (towards zero), - \constant{ROUND_HALF_EVEN}, - \constant{ROUND_HALF_UP} (away from zero), or - \constant{ROUND_UP} (away from zero). + \begin{itemize} + \item \constant{ROUND_CEILING} (towards \constant{Infinity}), + \item \constant{ROUND_DOWN} (towards zero), + \item \constant{ROUND_FLOOR} (towards \constant{-Infinity}), + \item \constant{ROUND_HALF_DOWN} (to nearest with ties going towards zero), + \item \constant{ROUND_HALF_EVEN} (to nearest with ties going to nearest even integer), + \item \constant{ROUND_HALF_UP} (to nearest with ties going away from zero), or + \item \constant{ROUND_UP} (away from zero). + \end{itemize} The \var{traps} and \var{flags} fields list any signals to be set. Generally, new contexts should only set traps and leave the flags clear. @@ -834,6 +836,8 @@ %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \subsection{Floating Point Notes \label{decimal-notes}} +\subsubsection{Mitigating round-off error with increased precision} + The use of decimal floating point eliminates decimal representation error (making it possible to represent \constant{0.1} exactly); however, some operations can still incur round-off error when non-zero digits exceed the @@ -881,6 +885,7 @@ Decimal("0.0060000") \end{verbatim} +\subsubsection{Special values} The number system for the \module{decimal} module provides special values including \constant{NaN}, \constant{sNaN}, \constant{-Infinity},

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python/dist/src/Doc/lib libdecimal.tex, 1.27, 1.28
by rhettinger＠users.sourceforge.net July 1, 2005

July 1, 2005

Update of /cvsroot/python/python/dist/src/Doc/lib In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv19113 Modified Files: libdecimal.tex Log Message: More info on rounding modes. Add sections for floating point notes. Index: libdecimal.tex =================================================================== RCS file: /cvsroot/python/python/dist/src/Doc/lib/libdecimal.tex,v retrieving revision 1.27 retrieving revision 1.28 diff -u -d -r1.27 -r1.28 --- libdecimal.tex 15 Jun 2005 16:53:31 -0000 1.27 +++ libdecimal.tex 1 Jul 2005 16:54:12 -0000 1.28 @@ -501,13 +501,15 @@ arithmetic operations in the context. The \var{rounding} option is one of: - \constant{ROUND_CEILING} (towards \constant{Infinity}), - \constant{ROUND_DOWN} (towards zero), - \constant{ROUND_FLOOR} (towards \constant{-Infinity}), - \constant{ROUND_HALF_DOWN} (towards zero), - \constant{ROUND_HALF_EVEN}, - \constant{ROUND_HALF_UP} (away from zero), or - \constant{ROUND_UP} (away from zero). + \begin{itemize} + \item \constant{ROUND_CEILING} (towards \constant{Infinity}), + \item \constant{ROUND_DOWN} (towards zero), + \item \constant{ROUND_FLOOR} (towards \constant{-Infinity}), + \item \constant{ROUND_HALF_DOWN} (to nearest with ties going towards zero), + \item \constant{ROUND_HALF_EVEN} (to nearest with ties going to nearest even integer), + \item \constant{ROUND_HALF_UP} (to nearest with ties going away from zero), or + \item \constant{ROUND_UP} (away from zero). + \end{itemize} The \var{traps} and \var{flags} fields list any signals to be set. Generally, new contexts should only set traps and leave the flags clear. @@ -834,6 +836,8 @@ %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \subsection{Floating Point Notes \label{decimal-notes}} +\subsubsection{Mitigating round-off error with increased precision} + The use of decimal floating point eliminates decimal representation error (making it possible to represent \constant{0.1} exactly); however, some operations can still incur round-off error when non-zero digits exceed the @@ -881,6 +885,7 @@ Decimal("0.0060000") \end{verbatim} +\subsubsection{Special values} The number system for the \module{decimal} module provides special values including \constant{NaN}, \constant{sNaN}, \constant{-Infinity},

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When will the Real Estate Bubble Burst? - Live Meeting July 21st on Alternative Investments
by Forex Managed Accounts July 1, 2005

July 1, 2005

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