This section lists previously described changes that may require
changes to your code:
yield is now always a keyword; if it's used as a
variable name in your code, a different name must be chosen.
For strings X and Y, X in Y now works
if X is more than one character long.
The int() type constructor will now return a long
integer instead of raising an OverflowError when a string
or floating-point number is too large to fit into an integer.
If you have Unicode strings that contain 8-bit characters, you
must declare the file's encoding (UTF-8, Latin-1, or whatever) by
adding a comment to the top of the file. See
section 3 for more information.
Calling Tcl methods through _tkinter no longer
returns only strings. Instead, if Tcl returns other objects those
objects are converted to their Python equivalent, if one exists, or
wrapped with a _tkinter.Tcl_Obj object if no Python equivalent
exists.
Large octal and hex literals such as
0xffffffff now trigger a FutureWarning. Currently
they're stored as 32-bit numbers and result in a negative value, but
in Python 2.4 they'll become positive long integers.
There are a few ways to fix this warning. If you really need a
positive number, just add an "L" to the end of the literal. If
you're trying to get a 32-bit integer with low bits set and have
previously used an expression such as (1 « 31), it's probably
clearest to start with all bits set and clear the desired upper bits.
For example, to clear just the top bit (bit 31), you could write
0xffffffffL &~(1L«31).
You can no longer disable assertions by assigning to __debug__.
The Distutils setup() function has gained various new
keyword arguments such as depends. Old versions of the
Distutils will abort if passed unknown keywords. A solution is to check
for the presence of the new get_distutil_options() function
in your setup.py and only uses the new keywords
with a version of the Distutils that supports them:
from distutils import core
kw = {'sources': 'foo.c', ...}
if hasattr(core, 'get_distutil_options'):
kw['depends'] = ['foo.h']
ext = Extension(**kw)
Using None as a variable name will now result in a
SyntaxWarning warning.
Names of extension types defined by the modules included with
Python now contain the module and a "." in front of the type
name.
