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| -rw-r--r-- | Misc/NEWS | 79 |
1 files changed, 78 insertions, 1 deletions
@@ -3,6 +3,36 @@ What's New in Python 2.1 alpha 1? Core language, builtins, and interpreter +- File objects have a new method, xreadlines(). This is the fastest + way to iterate over all lines in a file: + + for line in file.xreadlines(): + ...do something to line... + + See the xreadlines module (mentioned below) for how to do this for + other file-like objects. + +- Even if you don't use file.xreadlines(), you may expect a speedup on + line-by-line input. The file.readline() method has been optimized + quite a bit in platform-specific ways, both on Windows (using an + incredibly complex, but nevertheless thread-safe), and on systems + (like Linux) that support flockfile(), getc_unlocked(), and + funlockfile(). In addition, the fileinput module, while still slow, + has been sped up too, by using file.readlines(sizehint). + +- Support for run-time warnings has been added, including a new + command line option (-W) to specify the disposition of warnings. + See the description of the warnings module below. + +- Extensive changes have been made to the coercion code. This mostly + affects extension modules (which can now implement mixed-type + numerical operators without having to use coercion), but + occasionally, in boundary cases the coercion semantics have changed + subtly. Since this was a terrible gray area of the language, this + is considered an improvement. Also not that __rcmp__ is no longer + supported -- instead of calling __rcmp__, __cmp__ is called with + reversed arguments. + - The interpreter accepts now bytecode files on the command line even if they do not have a .pyc or .pyo extension. On Linux, after executing @@ -42,9 +72,32 @@ Core language, builtins, and interpreter item. Such algorithms normally end up running in quadratic time; using popitem() they can usually be made to run in linear time. - Standard library +- There's a new module, warnings, which implements a mechanism for + issuing and filtering warnings. There are some new built-in + exceptions that serve as warning categories, and a new command line + option, -W, to control warnings (e.g. -Wi ignores all warnings, -We + turns warnings into errors). warnings.warn(message[, category]) + issues a warning message; this can also be called from C as + PyErr_Warn(category, message). + +- A new module xreadlines was added. This exports a single factory + function, xreadlines(). The intention is that this code is the + absolutely fastest way to iterate over all lines in an open + file(-like) object: + + import xreadlines + for line in xreadlines.xreadlines(file): + ...do something to line... + + This is equivalent to the previous the speed record holder using + file.readlines(sizehint). Note that if file is a real file object + (as opposed to a file-like object), this is equivalent: + + for line in file.xreadlines(): + ...do something to line... + - The bisect module has new functions bisect_left, insort_left, bisect_right and insort_right. The old names bisect and insort are now aliases for bisect_right and insort_right. XXX_right @@ -54,6 +107,27 @@ Standard library right. Code that doesn't care where equal elements end up should continue to use the old, short names ("bisect" and "insort"). +- The SocketServer module now sets the allow_reuse_address flag by + default in the TCPServer class. + +- A new function, sys._getframe(), returns the stack frame pointer of + the caller. This is intended only as a building block for + higher-level mechanisms such as string interpolation. + +Build issues + +- On Linux (and possibly other Unix platforms), the readline and + _curses modules are automatically configured through + Modules/Setup.config. These, and the bsddb module (which was + already dynamically configured) are now built as shared libraries by + default. + +- Python now always uses its own (renamed) implementation of getopt() + -- there's too much variation among C library getopt() + implementations. + +- C++ compilers are better supported; the CXX macro is always set to a + C++ compiler if one is found. Windows changes @@ -63,6 +137,9 @@ Windows changes that, see the MS docs (you'll need to #define FD_SETSIZE and recompile Python from source). +- Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3 + subdirectory is no more! + What's New in Python 2.0? ========================= |