def compare_pyshipping_with_shotput():
from random import randint
from pyshipping import binpack_simple as binpack
from pyshipping.package import Package
from time import time
items = []
py_items = []
box_dims = sorted(
[randint(100, 200),
randint(100, 200),
randint(100, 200)])
num_items = 500
for _ in xrange(num_items):
item_dims = sorted(
[randint(20, 100),
randint(20, 100),
randint(20, 100)])
items.append(ItemTuple(str(volume(item_dims)), item_dims, 0))
py_items.append(Package((item_dims[0], item_dims[1], item_dims[2]), 0))
start = time()
items_packed = pack_boxes(box_dims, items)
end = time()
shotput = {
'num_parcels': len(items_packed),
'items_per_parcel': [len(parcel) for parcel in items_packed],
'time': end - start
}
py_box = Package((box_dims[0], box_dims[1], box_dims[2]), 0)
start = time()
py_items_packed = binpack.packit(py_box, py_items)
end = time()
pyshipping = {
'num_parcels': len(py_items_packed[0]),
'items_per_parcel': [len(parcel) for parcel in py_items_packed[0]],
'time': end - start
}
if len(items_packed) > len(py_items_packed[0]):
best_results = 'pyshipping'
elif len(items_packed) < len(py_items_packed[0]):
best_results = 'shotput'
else:
best_results = 'tie'
return {
'shotput': shotput,
'pyshipping': pyshipping,
'best_results': best_results
}
def binpack(packages, bin=None, iterlimit=5000):
"""Packs a list of Package() objects into a number of equal-sized bins.
Returns a list of bins listing the packages within the bins and a list of packages which can't be
packed because they are to big."""
if not bin:
bin = Package("600x400x400")
return allpermutations(packages, bin, iterlimit)
def allpermutations_helper(permuted, todo, maxcounter, callback, bin, bestpack, counter):
if not todo:
return counter + callback(bin, permuted, bestpack)
else:
others = todo[1:]
thispackage = todo[0]
for dimensions in set(permutations((thispackage[0], thispackage[1], thispackage[2]))):
thispackage = Package(dimensions, nosort=True)
if thispackage in bin:
counter = allpermutations_helper(permuted + [thispackage], others, maxcounter, callback,
bin, bestpack, counter)
if counter > maxcounter:
raise Timeout('more than %d iterations tries' % counter)
return counter
def test():
fd = open('testdata.txt')
vorher = 0
nachher = 0
start = time.time()
for line in fd:
packages = [Package(pack) for pack in line.strip().split()]
if not packages:
continue
bins, rest = binpack(packages)
if rest:
print("invalid data", rest, line)
else:
vorher += len(packages)
nachher += len(bins)
print(time.time() - start)
print(vorher, nachher, float(nachher) / vorher * 100)
def test(func):
fd = open('testdata.txt')
vorher = 0
nachher = 0
start = time.time()
counter = 0
for line in fd:
counter += 1
if counter > 450:
break
packages = [Package(pack) for pack in line.strip().split()]
if not packages:
continue
bins, rest = func(packages)
if rest:
print "invalid data", rest, line
else:
vorher += len(packages)
nachher += len(bins)
print time.time() - start,
print vorher, nachher, float(nachher) / vorher * 100
def test_pyshipping():
"""This test is to demonstrate how the pyshipping logic behaves with the
same inputs as test_bin_pack_complex, with the exception that pyShipping
allows for `Package` rotations along any axis.
`Packages`s are conceptually equivalent to `Parcel`s.
`bin`s are conceptually equivalent to `Compartment`s.
Still, we see that even in a case where a perfect fit is achievable, the
`pyshipping.bin_pack_simple` algorithm does not find it and instead ends
its iteration prematurely.
"""
bin = Package("5x4x3")
packages = [
Package("4x3x2"),
Package("1x3x3"),
Package("4x3x1"),
Package("2x1x3"),
Package("3x1x3"),
]
bins, rest = binpack(packages, bin)