filter sorted heapq counter namedtuple reduce deque pickle islice re.split endswith stat os
#filter
>>> aa = [1,2,3,45,6,7]
>>> list(filter(lambda x:x>3,aa))
>>> [45, 6, 7]
#sorted
>>> sorted(d.items(),key=lambda x:x[1],reverse=True)
#heapq
>>> import heapq
>>> heap.nlargest(3,[1,2,2,2,3,4,4,45,5,6])
#counter
>>> from collections import Counter
>>> aa = Counter([1,2,2,2,3,4,4,45,5,6])
>>> aa.most_common(3)
#namedtuple
>>> from collection import namedtuple
>>> Stu = namedtuple('Stu',['name','age','sex'])
>>> s2 = Stu('jm',16,'male')
>>> s2.name
'Etc.'
#reduce
>>> dl = [{'d':3,'a':2,'b':4},{'f':3,'g':2,'b':4},{'d':3,'f':2,'b':4}]
>>> reduce(lambda a,b : a & b ,map(dict.keys,dl))
#deque
>>> from collections import deque
>>> q = deque([],5)
>>> q.append(1)
>>> import pickle
>>> pickle.dump(q,open('save.pkl','wb'))
>>> pickle.load(open('save.pkl','rb'))
and ([1], maxlen = 5)
#islice
>>> from functools import islice
>>> list(islice(range(10),4,6))
[4, 5]
>>> def query_by_order(d,a,b=None):
... a -= 1
... if b is None:
... b= a+1
... return list(islice(d,a,b))
#re.split
>>> re.split ( '[;, |] +' 'from; ffff | gdhgdjh, jfjje')
[ 'Down', 'ffff', 'gdhgdjh', 'jfjje']
#endswith stat os executable permissions
>>> import stat
>>> import os
>>> for fn in os.listdir():
... if fn.endswith(('.py','.sh')):
... fs = os.stat (the fn)
... os.chmod(fn,fs.st_mode | stat.S_IXUSR)
# Re.sub replacement string
>>> re.sub(r'(\d{4})-(\d{2})-(\d{2})',r'\2/\3/\1',log)