>>> list=[]>>> app=[list,list,list]>>> app[[], [], []]>>> app[1].append(1)>>> app[[1], [1], [1]]>>> id(app[1])1666670423944>>> id(app[2])1666670423944

>>> app=[1,‘‘,"cat",[]]>>> for i in app:	print(app[i])

>>> for i in app:	print(i)1cat[]>>> for i in app:	if i:		print(i)1cat>>> [i for i in app][1, ‘‘, ‘cat‘, []]>>> [i for i in app if i][1, ‘cat‘]

>>> any(w!=0 for w in app)True>>> all(w!=‘‘ for w in app)False

>>> t=‘ass‘,33,‘‘>>> t(‘ass‘, 33, ‘‘)

>>> s(2, 5, 3, 1, 6, 7, 95, 3)>>> [n for n in s][2, 5, 3, 1, 6, 7, 95, 3]>>> [n for n in sorted(s)][1, 2, 3, 3, 5, 6, 7, 95]>>> [n for n in set(s)][1, 2, 3, 5, 6, 7, 95]>>> [n for n in reversed(s)][3, 95, 7, 6, 1, 3, 5, 2]>>> [n for n in s[::-1]][3, 95, 7, 6, 1, 3, 5, 2]>>> [n for n in set(s).difference(t)][1, 2, 3, 5, 6, 7, 95]>>> t=[1,23,4,5]>>> [n for n in set(s).difference(t)][2, 3, 6, 7, 95]>>> [n for n in random.shuffle(s)]

>>> text=open(r"C:\Users\BNC-PC\Desktop\text.txt","r").read()>>> len(text)34176>>> cut=int(0.9*len(text))>>> training_data,test_data=http://www.mamicode.com/text[:cut],text[cut:]>

>>> words=‘我 是 中国 人 ， 我 爱 祖国‘.split()>>> worelen=[w for w in words]>>> worelen[‘我‘, ‘是‘, ‘中国‘, ‘人‘, ‘，‘, ‘我‘, ‘爱‘, ‘祖国‘]>>> ‘=‘.join(w for w in worelen)‘我=是=中国=人=，=我=爱=祖国‘

def bncsum(m,n):    sum=0    if n:        sum=m/n    else:        sum=n    print(sum)>>> bncsum(4,5)0.8>>> bncsum(4,0)0>>> help(bncsum)Help on function bncsum in module __main__:bncsum(m, n)