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Diffstat (limited to 'Misc')
| -rw-r--r-- | Misc/NEWS | 44 |
1 files changed, 44 insertions, 0 deletions
@@ -3,6 +3,43 @@ What's New in Python 2.2a3? Core ++ Overflowing operations on plain ints now return a long int rather + than raising OverflowError. This is a partial implementation of PEP + 237. You can use -Wdefault::OverflowWarning to enable a warning for + this situation, and -Werror::OverflowWarning to revert to the old + OverflowError exception. + ++ A new command line option, -D<arg>, is added to control run-time + warnings for the use of classic division. (See PEP 238.) Possible + values are -Dold, -Dwarn, and -Dnew. The default is -Dold, meaning + the / operator has its classic meaning and no warnings are issued. + Using -Dwarn issues a run-time warning about all uses of classic + division for int, long, float and complex arguments. Using -Dnew is + questionable; it turns on new division by default, but only in the + __main__ module. You can usefully combine -Dwarn and -Dnew: this + gives the __main__ module new division, and warns about classic + division everywhere else. + ++ Many built-in types can now be subclassed. This applies to int, + long, float, str, unicode, and tuple. (The types complex, list and + dictionary can also be subclassed; this was introduced earlier.) + Note that restrictions apply when subclassing immutable built-in + types: you can only affect the value of the instance by overloading + __new__. You can add mutable attributes, and the subclass instances + will have a __dict__ attribute, but you cannot change the "value" + (as implemented by the base class) of an immutable subclass instance + once it is created. + ++ A new built-in type, super, has been added. This facilitates making + "cooperative super calls" in a multiple inheritance setting. For an + explanation, see http://www.python.org/2.2/descrintro.html#cooperation + ++ A new built-in type, getset, has been added. This enables the + creation of "computed attributes". Such attributes are implemented + by getter and setter functions (or only one of these for read-only + or write-only attributes), without the need to override + __getattr__. See http://www.python.org/2.2/descrintro.html#getset + + The syntax of floating-point and imaginary literals has been liberalized, to allow leading zeroes. Examples of literals now legal that were SyntaxErrors before: @@ -22,6 +59,9 @@ Library When read on a box where Python ints are 4 bytes, such values are converted to Python longs. ++ In restricted execution mode (using the rexec module), unmarshalling + code objects is no longer allowed. This plugs a security hole. + Tools Build @@ -44,6 +84,10 @@ API - remove calls to PyObject_AS_GC and PyObject_FROM_GC ++ Two new functions: PyString_FromFormat() and PyString_FromFormatV(). + These can be used safely to construct string objects from a + sprintf-style format string (similar to the format string supported + by PyErr_Format()). New platforms |