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# Borrowed from Alex Martelli's sort from Python cookbook using inlines
# 2x over fastest Python version -- again, maybe not worth the effort...
# Then again, 2x is 2x...
#
# C:\home\eric\wrk\scipy\weave\examples>python dict_sort.py
# Dict sort of 1000 items for 300 iterations:
# speed in python: 0.250999927521
# [0, 1, 2, 3, 4]
# speed in c: 0.110000014305
# speed up: 2.28
# [0, 1, 2, 3, 4]
# speed in c (scxx): 0.200000047684
# speed up: 1.25
# [0, 1, 2, 3, 4]
import sys
sys.path.insert(0,'..')
import inline_tools
def c_sort(adict):
assert(type(adict) is dict)
code = """
#line 24 "dict_sort.py"
py::list keys = adict.keys();
py::list items(keys.length());
keys.sort();
PyObject* item = NULL;
int N = keys.length();
for(int i = 0; i < N;i++)
{
item = PyList_GetItem(keys,i);
item = PyDict_GetItem(adict,item);
Py_XINCREF(item);
PyList_SetItem(items,i,item);
}
return_val = items;
"""
return inline_tools.inline(code,['adict'])
def c_sort2(adict):
assert(type(adict) is dict)
code = """
#line 44 "dict_sort.py"
py::list keys = adict.keys();
py::list items(keys.len());
keys.sort();
int N = keys.length();
for(int i = 0; i < N;i++)
{
items[i] = adict[int( keys[i] )];
}
return_val = items;
"""
return inline_tools.inline(code,['adict'],verbose=1)
# (IMHO) the simplest approach:
def sortedDictValues1(adict):
items = adict.items()
items.sort()
return [value for key, value in items]
# an alternative implementation, which
# happens to run a bit faster for large
# dictionaries on my machine:
def sortedDictValues2(adict):
keys = adict.keys()
keys.sort()
return [adict[key] for key in keys]
# a further slight speed-up on my box
# is to map a bound-method:
def sortedDictValues3(adict):
keys = adict.keys()
keys.sort()
return map(adict.get, keys)
import time
def sort_compare(a,n):
print 'Dict sort of %d items for %d iterations:'%(len(a),n)
t1 = time.time()
for i in range(n):
b=sortedDictValues3(a)
t2 = time.time()
py = (t2-t1)
print ' speed in python:', (t2 - t1)
print b[:5]
b=c_sort(a)
t1 = time.time()
for i in range(n):
b=c_sort(a)
t2 = time.time()
print ' speed in c (Python API):',(t2 - t1)
print ' speed up: %3.2f' % (py/(t2-t1))
print b[:5]
b=c_sort2(a)
t1 = time.time()
for i in range(n):
b=c_sort2(a)
t2 = time.time()
print ' speed in c (scxx):',(t2 - t1)
print ' speed up: %3.2f' % (py/(t2-t1))
print b[:5]
def setup_dict(m):
" does insertion order matter?"
import random
a = range(m)
d = {}
for i in range(m):
key = random.choice(a)
a.remove(key)
d[key]=key
return d
if __name__ == "__main__":
m = 1000
a = setup_dict(m)
n = 3000
sort_compare(a,n)
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