Collections Module

# Counter collection

from collections import Counter

l = [1, 1, 1, 2, 3]

print(Counter(l))

s = "asadadasadadada"

print(Counter(s))

ss = "How many times does each word show up in this sentence word word"

words = ss.split()

print(Counter(words))

c = Counter(words)

print(c.most_common(4))

# 결과

Counter({1: 3, 2: 1, 3: 1})

Counter({'a': 8, 'd': 5, 's': 2})

Counter({'word': 3, 'show': 1, 'many': 1, 'in': 1, 'each': 1, 'sentence': 1, 'up': 1, 'times': 1, 'How': 1, 'does': 1, 'this': 1})

[('word', 3), ('show', 1), ('many', 1), ('in', 1)]

# defaultdict

from collections import defaultdict

d = defaultdict(object)

d['one']

for item in d:

print(item)

d = defaultdict(lambda : 0)

print(d['one'])

d['two'] = 2

for k, v in d.items():

print("Key: {}, Value: {}".format(k, v))

# 결과

one

0

Key: one, Value: 0

Key: two, Value: 2

# OrderedDict

from collections import OrderedDict

d = OrderedDict()

d['a'] = 1

d['b'] = 2

d['c'] = 3

d['d'] = 4

for k, v in d.items():

print(k, v)

# 결과

a 1

b 2

c 3

d 4

# namedtuple

from collections import namedtuple

Dog = namedtuple('Dog', 'age breed name')

sam = Dog(age = 2, breed = 'Lab', name = 'sammy')

print(sam.age)

print(sam[0])

# 결과

2

2

# deque

from collections import deque

q = deque([1, 2, 3])

q.append(4)

q.append(5)

print(q)

q.popleft()

print(q)

q.pop()

print(q)

# 결과

deque([1, 2, 3, 4, 5])

deque([2, 3, 4, 5])

deque([2, 3, 4])

# list enumerate

ls = [1, 2, 3]

for index, value in enumerate(ls):

print("value: {}, index: {}".format(value, index))

# 결과

value: 1, index: 0

value: 2, index: 1

value: 3, index: 2