<PYTHON>[collections]

[collections]

- 내부 함수는 아래만 활용해 본다.

Counter()

deque()

defaultdict()

OrderedDict()

namedtuple()

 

 

1. Counter()

 

import re
import collections
 
cnt = collections.Counter()
 
words = ['flower','wing','star','flower','star','flower']
 
for w in words:
    cnt[w] += 1
 
print cnt
 
print list(cnt.elements())
 
chk = re.findall(r'\w+', open('test.txt').read().lower())
 
print collections.Counter(chk).most_common(10)
print collections.Counter(chk).most_common(5)
 
nCnt01 = collections.Counter(a=5, b=3, c=1, d=-1)
nCnt02 = collections.Counter(a=2, b=4, c=3, d=1)
nCnt03 = collections.Counter(a=5, b=3, c=1, d=-1)
 
print nCnt01.subtract(nCnt02)
print nCnt03 + nCnt02
print nCnt03 - nCnt02
print nCnt03 & nCnt02
print nCnt03 | nCnt02

 

 

 

 

2. deque()

 

import collections
 
d = collections.deque('flower')
 
for elem in d:
    print elem.upper()
 
d.append('a')
d.appendleft('z')
print d
print d.pop()
print d.popleft()
print list(d)
print d[0]
print d[-1]
print list(reversed(d))
print 'w' in d
d .extend(' teacher')
print d
d.rotate(1)
print d
d.rotate(-1)
print d
print collections.deque(reversed(d))
d.clear()
print d
d.extendleft('wing')
print d

 

 

 

 

3. defaultdict()

 

import collections
 
s = [('flower',3),('wing',1),('star',2),('sky',5)]
d = collections.defaultdict(list)
 
for k, v in s:
    d[k].append(v)
 
print d.items()
 
s = 'flowerflowerfflowwwwerrr'
d = collections.defaultdict(int)
for k in s:
    d[k] += 1
 
print d.items()
 
s = [('flower', 1),('wing',2),('flower',3),('wing',5),('wing',5)]
d = collections.defaultdict(set)
for k, v in s:
    d[k].add(v)
 
print d.items()

 

 

 

 

4. OrderedDict()

 

from collections import OrderedDict
 
d = {'flower': 2, 'wing': 1, 'star': 4, 'sky': 3}
 
print OrderedDict(sorted(d.items(), key=lambda t: t[0]))
print OrderedDict(sorted(d.items(), key=lambda t: t[1]))
print OrderedDict(sorted(d.items(), key=lambda t: len(t[0])))

 

 

 

5. namedtuple()

from collections import namedtuple
 
info = namedtuple('info', ['name', 'sex', 'area'])
 
name = 'wing flower sky snow'.split()
sex = 'mail femail'.split()
area = 'Korea USA'.split()
 
INFO = [info(n, s, a) for n in name for s in sex for a in area]
 
print(info)
for named in INFO:
    print(named)
print(type(INFO))
print(type(INFO[0]))