collections模块

from collections import namedtuple
Point = namedtuple(\'Point\',[\'x\',\'y\'])
p = Point(1,2)
print(p.x)  # 1
print(p.y)  # 2

print(isinstance(p,Point))  # True
print(isinstance(p,tuple))  # True

from collections import deque
q = deque([\'a\',\'b\',\'c\',\'d\'])
q.append(\'e\')
q.appendleft(\'A\')
print(q)    # deque([\'A\', \'a\', \'b\', \'c\', \'d\', \'e\'])
q.pop()
q.popleft()
print(q)    # deque([\'a\', \'b\', \'c\', \'d\'])

from collections import defaultdict
d = defaultdict(lambda:\'N/A\')
d[\'key1\'] = \'abc\'
print(d[\'key1\'])    # abc
print(d[\'key2\'])    # N/A

from collections import OrderedDict
d = dict([(\'a\',1),(\'b\',2),(\'c\',3)])
print(d)    # {\'a\': 1, \'c\': 3，\'b\': 2}   dict的key是无序的
od = OrderedDict([(\'a\',1),(\'b\',2),(\'c\',3)])
print(od)   # OrderedDict([(\'a\', 1), (\'b\', 2), (\'c\', 3)])   OrderedDict的key是有序的

from collections import OrderedDict
od = OrderedDict()
od[\'z\'] = 1
od[\'y\'] = 2
od[\'x\'] = 3
print(od.keys())    # odict_keys([\'z\', \'y\', \'x\'])

from collections import Counter
c = Counter()
for i in \'asdsadsafjzjk\':
    c[i]+=1
print(c)    # Counter({\'a\': 3, \'s\': 3, \'d\': 2, \'j\': 2, \'f\': 1, \'z\': 1, \'k\': 1})

cc = Counter(\'asdsadsafjzjk\')
print(cc)   # Counter({\'a\': 3, \'s\': 3, \'d\': 2, \'j\': 2, \'f\': 1, \'z\': 1, \'k\': 1})