This introduces:
- A new operator // that means floor division (the kind of division
where 1/2 is 0).
- The "future division" statement ("from __future__ import division)
which changes the meaning of the / operator to implement "true
division" (where 1/2 is 0.5).
- New overloadable operators __truediv__ and __floordiv__.
- New slots in the PyNumberMethods struct for true and floor division,
new abstract APIs for them, new opcodes, and so on.
I emphasize that without the future division statement, the semantics
of / will remain unchanged until Python 3.0.
Not yet implemented are warnings (default off) when / is used with int
or long arguments.
This has been on display since 7/31 as SF patch #443474.
Flames to /dev/null.
- Add an explicit call to PyType_Ready(&PyList_Type) to pythonrun.c
(just for the heck of it, really -- we should either explicitly
ready all types, or none).
sees it (test_iter.py is unchanged).
- Added a tp_iternext slot, which calls the iterator's next() method;
this is much faster for built-in iterators over built-in types
such as lists and dicts, speeding up pybench's ForLoop with about
25% compared to Python 2.1. (Now there's a good argument for
iterators. ;-)
- Renamed the built-in sequence iterator SeqIter, affecting the C API
functions for it. (This frees up the PyIter prefix for generic
iterator operations.)
- Added PyIter_Check(obj), which checks that obj's type has a
tp_iternext slot and that the proper feature flag is set.
- Added PyIter_Next(obj) which calls the tp_iternext slot. It has a
somewhat complex return condition due to the need for speed: when it
returns NULL, it may not have set an exception condition, meaning
the iterator is exhausted; when the exception StopIteration is set
(or a derived exception class), it means the same thing; any other
exception means some other error occurred.
new slot tp_iter in type object, plus new flag Py_TPFLAGS_HAVE_ITER
new C API PyObject_GetIter(), calls tp_iter
new builtin iter(), with two forms: iter(obj), and iter(function, sentinel)
new internal object types iterobject and calliterobject
new exception StopIteration
new opcodes for "for" loops, GET_ITER and FOR_ITER (also supported by dis.py)
new magic number for .pyc files
new special method for instances: __iter__() returns an iterator
iteration over dictionaries: "for x in dict" iterates over the keys
iteration over files: "for x in file" iterates over lines
TODO:
documentation
test suite
decide whether to use a different way to spell iter(function, sentinal)
decide whether "for key in dict" is a good idea
use iterators in map/filter/reduce, min/max, and elsewhere (in/not in?)
speed tuning (make next() a slot tp_next???)
discussion on python-dev. 'from mod import *' is still banned except
at the module level.
Fix value for special NOOPT entry in symtable. Initialze to 0 instead
of None, so that later uses of PyInt_AS_LONG() are valid. (Bug
reported by Donn Cave.)
replace local REPR macros with PyObject_REPR in object.h
except that it always returns Unicode objects.
A new C API PyObject_Unicode() is also provided.
This closes patch #101664.
Written by Marc-Andre Lemburg. Copyright assigned to Guido van Rossum.
It's hard to sort out what the bug was, exactly. So, Big Hammer:
1. Python shouldn't be in the business of #define'ing NULL, period.
2. Users of the Python C API shouldn't be in the business of not including
Python.h, period.
Hence:
1. Removed all #define's of NULL in Python source code (pyport.h and
object.h).
2. Since we're *relying* on stdio.h defining NULL, put an #error in
Python.h after its #include of stdio.h if NULL isn't defined then.
comments, docstrings or error messages. I fixed two minor things in
test_winreg.py ("didn't" -> "Didn't" and "Didnt" -> "Didn't").
There is a minor style issue involved: Guido seems to have preferred English
grammar (behaviour, honour) in a couple places. This patch changes that to
American, which is the more prominent style in the source. I prefer English
myself, so if English is preferred, I'd be happy to supply a patch myself ;)
Stein -- thanks!). Incidentally removed all the Py_PROTO macros
from object.h, as they prevented my editor from magically finding
the definitions of the "coercion", "cmpfunc" and "reprfunc"
typedefs that were being redundantly applied in longobject.c.
errors in some of the hash algorithms. For exmaple, in float_hash and
complex_hash a certain part of the value is not included in the hash
calculation. See Tim's, Guido's, and my discussion of this on
python-dev in May under the title "fix float_hash and complex_hash for
64-bit *nix"
(2) The hash algorithms that use pointers (e.g. func_hash, code_hash)
are universally not correct on Win64 (they assume that sizeof(long) ==
sizeof(void*))
As well, this patch significantly cleans up the hash code. It adds the
two function _Py_HashDouble and _PyHash_VoidPtr that the various
hashing routine are changed to use.
These help maintain the hash function invariant: (a==b) =>
(hash(a)==hash(b))) I have added Lib/test/test_hash.py and
Lib/test/output/test_hash to test this for some cases.
This patch modifies the type structures of objects that
participate in GC. The object's tp_basicsize is increased when
GC is enabled. GC information is prefixed to the object to
maintain binary compatibility. GC objects also define the
tp_flag Py_TPFLAGS_GC.
Improvements:
- does no longer need any extra memory
- has no relationship to tstate
- works in debug mode
- can easily be modified for free threading (hi Greg:)
Side effects:
Trashcan does change the order of object destruction.
Prevending that would be quite an immense effort, as
my attempts have shown. This version works always
the same, with debug mode or not. The slightly
changed destruction order should therefore be no problem.
Algorithm:
While the old idea of delaying the destruction of some
obejcts at a certain recursion level was kept, we now
no longer aloocate an object to hold these objects.
The delayed objects are instead chained together
via their ob_type field. The type is encoded via
ob_refcnt. When it comes to the destruction of the
chain of waiting objects, the topmost object is popped
off the chain and revived with type and refcount 1,
then it gets a normal Py_DECREF.
I am confident that this solution is near optimum
for minimizing side effects and code bloat.
/* More standard operations (at end for binary compatibility) */
should now be:
/* More standard operations (here for binary compatibility) */
since they're no longer at the end!
Added wrapping macros to dictobject.c, listobject.c, tupleobject.c,
frameobject.c, traceback.c that safely prevends core dumps
on stack overflow. Macros and functions in object.c, object.h.
The method is an "elevator destructor" that turns cascading
deletes into tail recursive behavior when some limit is hit.
a new proc type (objobjproc), a new slot sq_contains to
PySequenceMethods, and a new flag Py_TPFLAGS_HAVE_SEQUENCE_IN to
Py_TPFLAGS_DEFAULT. More to follow.
Add a new member to the PyBufferProcs struct, bf_getcharbuffer. For
backward compatibility, this member should only be used (this includes
testing for NULL!) when the flag Py_TPFLAGS_HAVE_GETCHARBUFFER is set
in the type structure, below. Note that if its flag is not set, we
may be looking at an extension module compiled for 1.5.1, which will
have garbage at the bf_getcharbuffer member (because the struct wasn't
as long then). If the flag is one, the pointer may still be NULL.
The function found at this member is used in a similar manner as
bf_getreadbuffer, but it is known to point to 8-bit character data.
(See discussion in getargs.c checked in later.)
As a general feature for extending the type structure and the various
structures that (may) hang off it in a backwards compatible way, we
rename the tp_xxx4 "spare" slot to tp_flags. In 1.5.1 and before,
this slot was always zero. In 1.5.1, it may contain various flags
indicating extra fields that weren't present in 1.5.1. The only flag
defined so far is for the bf_getcharbuffer member of the PyBufferProcs
struct.
Note that the new spares (tp_xxx5 - tp_xxx8), once they become used,
should also be protected by a flag (or flags) in tp_flags.
Py_DECREF, to reduce the warnings when compiling with reference count
debugging on. (There are still warnings for each call to
_Py_NewReference -- too bad.)
Guido van Rossum
Martin v. Löwis
Tim Peters
Fred Drake
Jeremy Hylton
Barry Warsaw
Marc-André Lemburg
Neil Schemenauer
Thomas Wouters
Greg Stein