- Specialcase extended slices that amount to a shallow copy the same way as
is done for simple slices, in the tuple, string and unicode case.
- Specialcase step-1 extended slices to optimize the common case for all
involved types.
- For lists, allow extended slice assignment of differing lengths as long
as the step is 1. (Previously, 'l[:2:1] = []' failed even though
'l[:2] = []' and 'l[:2:None] = []' do not.)
- Implement extended slicing for buffer, array, structseq, mmap and
UserString.UserString.
- Implement slice-object support (but not non-step-1 slice assignment) for
UserString.MutableString.
- Add tests for all new functionality.
but disabled then because str and unicode strings gave different
results. The implementations were repaired later during the
sprint, but the new test remained disabled.
The new split functions use a preallocated list. Added tests which exceed
the preallocation size, to exercise list appends/resizes.
Also added more edge case tests.
the Need For Speed sprint coding. Includes commented out overflow tests
which will be uncommented once the code is fixed.
This test will break the 8-bit string tests because
"".replace("", "A") == "" when it should == "A"
We have a fix for it, which should be added tomorrow.
[ 1327110 ] wrong TypeError traceback in generator expressions
by removing the code that can stomp on the users' TypeError raised by the
iterable argument to ''.join() -- PySequence_Fast (now?) gives a perfectly
reasonable message itself. Also, a couple of tests.
* Speed-up "x in y" where x has more than one character.
The existing code made excessive calls to the expensive memcmp() function.
The new code uses memchr() to rapidly find a start point for memcmp().
In addition to knowing that the first character is a match, the new code
also checks that the last character is a match. This significantly reduces
the incidence of false starts (saving memcmp() calls and making quadratic
behavior less likely).
Improves the timings on:
python -m timeit -r7 -s"x='a'*1000" "'ab' in x"
python -m timeit -r7 -s"x='a'*1000" "'bc' in x"
Once this code has proven itself, then string_find_internal() should refer
to it rather than running its own version. Also, something similar may
apply to unicode objects.
s.join([t]) is t
for (s, t) in (str, str), (unicode, unicode), and (str, unicode).
For (unicode, str), verify that it's *not* t (the result is promoted
to unicode instead). Also verify that when t is a subclass of str or
unicode that "the right thing" happens.
unicodedata.east_asian_width(). You can still implement your own
simple width() function using it like this:
def width(u):
w = 0
for c in unicodedata.normalize('NFC', u):
cwidth = unicodedata.east_asian_width(c)
if cwidth in ('W', 'F'): w += 2
else: w += 1
return w
* Doc - add doc for when functions were added
* UserString
* string object methods
* string module functions
'chars' is used for the last parameter everywhere.
These changes will be backported, since part of the changes
have already been made, but they were inconsistent.
between str, unicode, UserString and the string module
as possible. This increases code coverage in stringobject.c
from 83% to 86% and should help keep the string classes
in sync in the future. From SF patch #662807
Thomas Wouters
Neal Norwitz
Kristján Valur Jónsson
Raymond Hettinger
Georg Brandl
Tim Peters
Fredrik Lundh
Andrew Dalke
Martin v. Löwis
Michael W. Hudson
Walter Dörwald
Hye-Shik Chang
Neil Schemenauer