diff options
Diffstat (limited to 'Doc/api')
| -rw-r--r-- | Doc/api/abstract.tex | 6 | ||||
| -rw-r--r-- | Doc/api/concrete.tex | 44 | ||||
| -rw-r--r-- | Doc/api/exceptions.tex | 47 | ||||
| -rw-r--r-- | Doc/api/newtypes.tex | 96 | ||||
| -rw-r--r-- | Doc/api/refcounts.dat | 2 |
5 files changed, 158 insertions, 37 deletions
diff --git a/Doc/api/abstract.tex b/Doc/api/abstract.tex index f50ebc41fa..7c742a0be6 100644 --- a/Doc/api/abstract.tex +++ b/Doc/api/abstract.tex @@ -255,6 +255,8 @@ determination. \NULL, indicating that no arguments are provided. Returns the result of the call on success, or \NULL{} on failure. This is the equivalent of the Python expression \samp{\var{callable}(*\var{args})}. + Note that if you only pass \ctype{PyObject *} args, + \cfunction{PyObject_CallFunctionObjArgs} is a faster alternative. \end{cfuncdesc} @@ -268,6 +270,8 @@ determination. indicating that no arguments are provided. Returns the result of the call on success, or \NULL{} on failure. This is the equivalent of the Python expression \samp{\var{o}.\var{method}(\var{args})}. + Note that if you only pass \ctype{PyObject *} args, + \cfunction{PyObject_CallMethodObjArgs} is a faster alternative. \end{cfuncdesc} @@ -624,7 +628,7 @@ determination. Returns the result of right shifting \var{o1} by \var{o2} on success, or \NULL{} on failure. The operation is done \emph{in-place} when \var{o1} supports it. This is the equivalent - of the Python statement \samp{\var{o1} >\code{>=} \var{o2}}. + of the Python statement \samp{\var{o1} >>= \var{o2}}. \end{cfuncdesc} diff --git a/Doc/api/concrete.tex b/Doc/api/concrete.tex index 1982bae67f..10247ab750 100644 --- a/Doc/api/concrete.tex +++ b/Doc/api/concrete.tex @@ -245,7 +245,7 @@ booleans. The following macros are available, however. \end{csimplemacrodesc} \begin{cfuncdesc}{PyObject*}{PyBool_FromLong}{long v} - Return a new reference to \constant{Py_True} or \constant{Py_False} + Return a new reference to \constant{Py_True} or \constant{Py_False} depending on the truth value of \var{v}. \versionadded{2.3} \end{cfuncdesc} @@ -618,12 +618,24 @@ parameter and are called with a non-string parameter. exactly to the format characters in the \var{format} string. The following format characters are allowed: + % This should be exactly the same as the table in PyErr_Format. + % One should just refer to the other. + + % The descriptions for %zd and %zu are wrong, but the truth is complicated + % because not all compilers support the %z width modifier -- we fake it + % when necessary via interpolating PY_FORMAT_SIZE_T. + + % %u, %lu, %zu should have "new in Python 2.5" blurbs. + \begin{tableiii}{l|l|l}{member}{Format Characters}{Type}{Comment} \lineiii{\%\%}{\emph{n/a}}{The literal \% character.} \lineiii{\%c}{int}{A single character, represented as an C int.} \lineiii{\%d}{int}{Exactly equivalent to \code{printf("\%d")}.} + \lineiii{\%u}{unsigned int}{Exactly equivalent to \code{printf("\%u")}.} \lineiii{\%ld}{long}{Exactly equivalent to \code{printf("\%ld")}.} - \lineiii{\%zd}{long}{Exactly equivalent to \code{printf("\%zd")}.} + \lineiii{\%lu}{unsigned long}{Exactly equivalent to \code{printf("\%lu")}.} + \lineiii{\%zd}{Py_ssize_t}{Exactly equivalent to \code{printf("\%zd")}.} + \lineiii{\%zu}{size_t}{Exactly equivalent to \code{printf("\%zu")}.} \lineiii{\%i}{int}{Exactly equivalent to \code{printf("\%i")}.} \lineiii{\%x}{int}{Exactly equivalent to \code{printf("\%x")}.} \lineiii{\%s}{char*}{A null-terminated C character array.} @@ -632,6 +644,10 @@ parameter and are called with a non-string parameter. guaranteed to start with the literal \code{0x} regardless of what the platform's \code{printf} yields.} \end{tableiii} + + An unrecognized format character causes all the rest of the format + string to be copied as-is to the result string, and any extra + arguments discarded. \end{cfuncdesc} \begin{cfuncdesc}{PyObject*}{PyString_FromFormatV}{const char *format, @@ -687,7 +703,7 @@ parameter and are called with a non-string parameter. \var{size})}. It must not be deallocated. If \var{string} is a Unicode object, this function computes the default encoding of \var{string} and operates on that. If \var{string} is not a string - object at all, \cfunction{PyString_AsStringAndSize()} returns + object at all, \cfunction{PyString_AsStringAndSize()} returns \code{-1} and raises \exception{TypeError}. \end{cfuncdesc} @@ -949,7 +965,7 @@ These APIs can be used for fast direct character conversions: \end{cfuncdesc} \begin{cfuncdesc}{double}{Py_UNICODE_TONUMERIC}{Py_UNICODE ch} - Return the character \var{ch} converted to a (positive) double. + Return the character \var{ch} converted to a double. Return \code{-1.0} if this is not possible. This macro does not raise exceptions. \end{cfuncdesc} @@ -1393,7 +1409,7 @@ The following codec API is special in that maps Unicode to Unicode. The \var{mapping} table must map Unicode ordinal integers to Unicode ordinal integers or None (causing deletion of the character). - Mapping tables need only provide the method{__getitem__()} + Mapping tables need only provide the \method{__getitem__()} interface; dictionaries and sequences work well. Unmapped character ordinals (ones which cause a \exception{LookupError}) are left untouched and are copied as-is. @@ -1494,7 +1510,7 @@ They all return \NULL{} or \code{-1} if an exception occurs. Return 1 if \var{substr} matches \var{str}[\var{start}:\var{end}] at the given tail end (\var{direction} == -1 means to do a prefix match, \var{direction} == 1 a suffix match), 0 otherwise. - Return \code{-1} if an error occurred. + Return \code{-1} if an error occurred. \end{cfuncdesc} \begin{cfuncdesc}{Py_ssize_t}{PyUnicode_Find}{PyObject *str, @@ -3013,7 +3029,7 @@ Macros for the convenience of modules implementing the DB API: \subsection{Set Objects \label{setObjects}} -\sectionauthor{Raymond D. Hettinger}{python@rcn.com} +\sectionauthor{Raymond D. Hettinger}{python@rcn.com} \obindex{set} \obindex{frozenset} @@ -3022,8 +3038,8 @@ Macros for the convenience of modules implementing the DB API: This section details the public API for \class{set} and \class{frozenset} objects. Any functionality not listed below is best accessed using the either the abstract object protocol (including -\cfunction{PyObject_CallMethod()}, \cfunction{PyObject_RichCompareBool()}, -\cfunction{PyObject_Hash()}, \cfunction{PyObject_Repr()}, +\cfunction{PyObject_CallMethod()}, \cfunction{PyObject_RichCompareBool()}, +\cfunction{PyObject_Hash()}, \cfunction{PyObject_Repr()}, \cfunction{PyObject_IsTrue()}, \cfunction{PyObject_Print()}, and \cfunction{PyObject_GetIter()}) or the abstract number protocol (including @@ -3040,7 +3056,7 @@ or the abstract number protocol (including block of memory for medium and large sized sets (much like list storage). None of the fields of this structure should be considered public and are subject to change. All access should be done through the - documented API rather than by manipulating the values in the structure. + documented API rather than by manipulating the values in the structure. \end{ctypedesc} @@ -3059,7 +3075,7 @@ The following type check macros work on pointers to any Python object. Likewise, the constructor functions work with any iterable Python object. \begin{cfuncdesc}{int}{PyAnySet_Check}{PyObject *p} - Return true if \var{p} is a \class{set} object, a \class{frozenset} + Return true if \var{p} is a \class{set} object, a \class{frozenset} object, or an instance of a subtype. \end{cfuncdesc} @@ -3112,7 +3128,7 @@ The following functions and macros are available for instances of function does not automatically convert unhashable sets into temporary frozensets. Raise a \exception{TypeError} if the \var{key} is unhashable. Raise \exception{PyExc_SystemError} if \var{anyset} is not a \class{set}, - \class{frozenset}, or an instance of a subtype. + \class{frozenset}, or an instance of a subtype. \end{cfuncdesc} The following functions are available for instances of \class{set} or @@ -3134,7 +3150,7 @@ its subtypes but not for instances of \class{frozenset} or its subtypes. unhashable. Unlike the Python \method{discard()} method, this function does not automatically convert unhashable sets into temporary frozensets. Raise \exception{PyExc_SystemError} if \var{set} is an not an instance - of \class{set} or its subtype. + of \class{set} or its subtype. \end{cfuncdesc} \begin{cfuncdesc}{PyObject*}{PySet_Pop}{PyObject *set} @@ -3142,7 +3158,7 @@ its subtypes but not for instances of \class{frozenset} or its subtypes. and removes the object from the \var{set}. Return \NULL{} on failure. Raise \exception{KeyError} if the set is empty. Raise a \exception{SystemError} if \var{set} is an not an instance - of \class{set} or its subtype. + of \class{set} or its subtype. \end{cfuncdesc} \begin{cfuncdesc}{int}{PySet_Clear}{PyObject *set} diff --git a/Doc/api/exceptions.tex b/Doc/api/exceptions.tex index 62f713bc6f..6dbe8184c3 100644 --- a/Doc/api/exceptions.tex +++ b/Doc/api/exceptions.tex @@ -132,13 +132,32 @@ error indicator for each thread. codes, similar to \cfunction{printf()}. The \code{width.precision} before a format code is parsed, but the width part is ignored. - \begin{tableii}{c|l}{character}{Character}{Meaning} - \lineii{c}{Character, as an \ctype{int} parameter} - \lineii{d}{Number in decimal, as an \ctype{int} parameter} - \lineii{x}{Number in hexadecimal, as an \ctype{int} parameter} - \lineii{s}{A string, as a \ctype{char *} parameter} - \lineii{p}{A hex pointer, as a \ctype{void *} parameter} - \end{tableii} + % This should be exactly the same as the table in PyString_FromFormat. + % One should just refer to the other. + + % The descriptions for %zd and %zu are wrong, but the truth is complicated + % because not all compilers support the %z width modifier -- we fake it + % when necessary via interpolating PY_FORMAT_SIZE_T. + + % %u, %lu, %zu should have "new in Python 2.5" blurbs. + + \begin{tableiii}{l|l|l}{member}{Format Characters}{Type}{Comment} + \lineiii{\%\%}{\emph{n/a}}{The literal \% character.} + \lineiii{\%c}{int}{A single character, represented as an C int.} + \lineiii{\%d}{int}{Exactly equivalent to \code{printf("\%d")}.} + \lineiii{\%u}{unsigned int}{Exactly equivalent to \code{printf("\%u")}.} + \lineiii{\%ld}{long}{Exactly equivalent to \code{printf("\%ld")}.} + \lineiii{\%lu}{unsigned long}{Exactly equivalent to \code{printf("\%lu")}.} + \lineiii{\%zd}{Py_ssize_t}{Exactly equivalent to \code{printf("\%zd")}.} + \lineiii{\%zu}{size_t}{Exactly equivalent to \code{printf("\%zu")}.} + \lineiii{\%i}{int}{Exactly equivalent to \code{printf("\%i")}.} + \lineiii{\%x}{int}{Exactly equivalent to \code{printf("\%x")}.} + \lineiii{\%s}{char*}{A null-terminated C character array.} + \lineiii{\%p}{void*}{The hex representation of a C pointer. + Mostly equivalent to \code{printf("\%p")} except that it is + guaranteed to start with the literal \code{0x} regardless of + what the platform's \code{printf} yields.} + \end{tableiii} An unrecognized format character causes all the rest of the format string to be copied as-is to the result string, and any extra @@ -272,8 +291,8 @@ error indicator for each thread. command line documentation. There is no C API for warning control. \end{cfuncdesc} -\begin{cfuncdesc}{int}{PyErr_WarnExplicit}{PyObject *category, - const char *message, const char *filename, int lineno, +\begin{cfuncdesc}{int}{PyErr_WarnExplicit}{PyObject *category, + const char *message, const char *filename, int lineno, const char *module, PyObject *registry} Issue a warning message with explicit control over all warning attributes. This is a straightforward wrapper around the Python @@ -314,12 +333,14 @@ error indicator for each thread. The \var{name} argument must be the name of the new exception, a C string of the form \code{module.class}. The \var{base} and \var{dict} arguments are normally \NULL. This creates a class - object derived from the root for all exceptions, the built-in name - \exception{Exception} (accessible in C as \cdata{PyExc_Exception}). + object derived from \exception{Exception} (accessible in C as + \cdata{PyExc_Exception}). + The \member{__module__} attribute of the new class is set to the first part (up to the last dot) of the \var{name} argument, and the class name is set to the last part (after the last dot). The - \var{base} argument can be used to specify an alternate base class. + \var{base} argument can be used to specify alternate base classes; + it can either be only one class or a tuple of classes. The \var{dict} argument can be used to specify a dictionary of class variables and methods. \end{cfuncdesc} @@ -399,5 +420,5 @@ are derived from \exception{BaseException}. \withsubitem{(built-in exception)}{\ttindex{BaseException}} String exceptions are still supported in the interpreter to allow -existing code to run unmodified, but this will also change in a future +existing code to run unmodified, but this will also change in a future release. diff --git a/Doc/api/newtypes.tex b/Doc/api/newtypes.tex index 2d758b08ca..28f77f7b71 100644 --- a/Doc/api/newtypes.tex +++ b/Doc/api/newtypes.tex @@ -883,8 +883,39 @@ The following three fields only exist if the \begin{cmemberdesc}{PyTypeObject}{traverseproc}{tp_traverse} An optional pointer to a traversal function for the garbage collector. This is only used if the \constant{Py_TPFLAGS_HAVE_GC} - flag bit is set. More information in section - \ref{supporting-cycle-detection} about garbage collection. + flag bit is set. More information about Python's garbage collection + scheme can be found in section \ref{supporting-cycle-detection}. + + The \member{tp_traverse} pointer is used by the garbage collector + to detect reference cycles. A typical implementation of a + \member{tp_traverse} function simply calls \cfunction{Py_VISIT()} on + each of the instance's members that are Python objects. For exampe, this + is function \cfunction{local_traverse} from the \module{thread} extension + module: + + \begin{verbatim} + static int + local_traverse(localobject *self, visitproc visit, void *arg) + { + Py_VISIT(self->args); + Py_VISIT(self->kw); + Py_VISIT(self->dict); + return 0; + } + \end{verbatim} + + Note that \cfunction{Py_VISIT()} is called only on those members that can + participate in reference cycles. Although there is also a + \samp{self->key} member, it can only be \NULL{} or a Python string and + therefore cannot be part of a reference cycle. + + On the other hand, even if you know a member can never be part of a cycle, + as a debugging aid you may want to visit it anyway just so the + \module{gc} module's \function{get_referents()} function will include it. + + Note that \cfunction{Py_VISIT()} requires the \var{visit} and \var{arg} + parameters to \cfunction{local_traverse} to have these specific names; + don't name them just anything. This field is inherited by subtypes together with \member{tp_clear} and the \constant{Py_TPFLAGS_HAVE_GC} flag bit: the flag bit, @@ -896,8 +927,57 @@ The following three fields only exist if the \begin{cmemberdesc}{PyTypeObject}{inquiry}{tp_clear} An optional pointer to a clear function for the garbage collector. This is only used if the \constant{Py_TPFLAGS_HAVE_GC} flag bit is - set. More information in section - \ref{supporting-cycle-detection} about garbage collection. + set. + + The \member{tp_clear} member function is used to break reference + cycles in cyclic garbage detected by the garbage collector. Taken + together, all \member{tp_clear} functions in the system must combine to + break all reference cycles. This is subtle, and if in any doubt supply a + \member{tp_clear} function. For example, the tuple type does not + implement a \member{tp_clear} function, because it's possible to prove + that no reference cycle can be composed entirely of tuples. Therefore + the \member{tp_clear} functions of other types must be sufficient to + break any cycle containing a tuple. This isn't immediately obvious, and + there's rarely a good reason to avoid implementing \member{tp_clear}. + + Implementations of \member{tp_clear} should drop the instance's + references to those of its members that may be Python objects, and set + its pointers to those members to \NULL{}, as in the following example: + + \begin{verbatim} + static int + local_clear(localobject *self) + { + Py_CLEAR(self->key); + Py_CLEAR(self->args); + Py_CLEAR(self->kw); + Py_CLEAR(self->dict); + return 0; + } + \end{verbatim} + + The \cfunction{Py_CLEAR()} macro should be used, because clearing + references is delicate: the reference to the contained object must not be + decremented until after the pointer to the contained object is set to + \NULL{}. This is because decrementing the reference count may cause + the contained object to become trash, triggering a chain of reclamation + activity that may include invoking arbitrary Python code (due to + finalizers, or weakref callbacks, associated with the contained object). + If it's possible for such code to reference \var{self} again, it's + important that the pointer to the contained object be \NULL{} at that + time, so that \var{self} knows the contained object can no longer be + used. The \cfunction{Py_CLEAR()} macro performs the operations in a + safe order. + + Because the goal of \member{tp_clear} functions is to break reference + cycles, it's not necessary to clear contained objects like Python strings + or Python integers, which can't participate in reference cycles. + On the other hand, it may be convenient to clear all contained Python + objects, and write the type's \member{tp_dealloc} function to + invoke \member{tp_clear}. + + More information about Python's garbage collection + scheme can be found in section \ref{supporting-cycle-detection}. This field is inherited by subtypes together with \member{tp_clear} and the \constant{Py_TPFLAGS_HAVE_GC} flag bit: the flag bit, @@ -910,10 +990,10 @@ The following three fields only exist if the An optional pointer to the rich comparison function. The signature is the same as for \cfunction{PyObject_RichCompare()}. - The function should return \code{1} if the requested comparison - returns true, \code{0} if it returns false. It should return - \code{-1} and set an exception condition when an error occurred - during the comparison. + The function should return the result of the comparison (usually + \code{Py_True} or \code{Py_False}). If the comparison is undefined, + it must return \code{Py_NotImplemented}, if another error occurred + it must return \code{NULL} and set an exception condition. This field is inherited by subtypes together with \member{tp_compare} and \member{tp_hash}: a subtype inherits all diff --git a/Doc/api/refcounts.dat b/Doc/api/refcounts.dat index 7bba011d77..ab6d865b04 100644 --- a/Doc/api/refcounts.dat +++ b/Doc/api/refcounts.dat @@ -1147,7 +1147,7 @@ PySet_Discard:PyObject*:key:-1:no effect if key not found PySet_New:PyObject*::+1: PySet_New:PyObject*:iterable:0: -PySet_Pop:PyObject*::0:or returns NULL and raises KeyError if set is empty +PySet_Pop:PyObject*::+1:or returns NULL and raises KeyError if set is empty PySet_Pop:PyObject*:set:0: PySet_Size:int::: |