[Python-Dev] timsort for jython

[Skip Montanaro]

    Patrick> Your flip comment has got me thinking about the "one best
    Patrick> idiom" for list appending. So I'll ask the question. Is there a
    Patrick> reason to want to get rid of list.append()? 

Certainly not for performance.  append is substantially faster that +=, at
least in part because of the list creation, especially if you cache the
method lookup. 

Skip

import time

def timefunc(s, args, *sargs, **kwds):
    t = time.time()
    apply(s, args+sargs, kwds)
    return time.time()-t

def appendit(l, o, n):
    append = l.append
    for i in xrange(n):
        append(o)

def extendit(l, o, n):
    extend = l.extend
    for i in xrange(n):
        extend([o])

def augassignit(l, o, n):
    for i in xrange(n):
        l += [o]

print "append small int:",
x = 0.0
for i in 1,2,3:
    x += timefunc(appendit, ([], 1, 100000))
print "%.3f" % (x/3)
print "aug assign small int:",
x = 0.0
for i in 1,2,3:
    x += timefunc(augassignit, ([], 1, 100000))
print "%.3f" % (x/3)
print "extend small int:",
x = 0.0
for i in 1,2,3:
    x += timefunc(extendit, ([], 1, 100000))
print "%.3f" % (x/3)