1.dict.get()

from numpy import *
labels=['a','b','d','n','s']
dict={}
a=labels[3];
b=labels[4];
dict[a]=dict.get(a,0)+1
dict[b]=dict.get(a,2)+1
print(dict)

{'n': 1, 's': 2}

2.sorted(),itemgetter()

#
from math import log
import operator
classCount={0:10,3:9,1:12}
sortedClassCount = sorted(classCount.items(), key=operator.itemgetter(0), reverse=True)
print(sortedClassCount)

[(3, 9), (1, 12), (0, 10)]

#
import operator
c = [('john', 'A', 15), ('jane', 'B', 12), ('dave', 'A', 10)]
#reverse降序排列，預設true。取C中一二維進行降序排列（字母和數字）
d=sorted(c, key=operator.itemgetter(1,2),reverse=True)
print(d)

[('dave', 'A', 10), ('john', 'A', 15), ('jane', 'B', 12)]

#
import operator
classCount={0:10,3:9,1:12}
sortedClassCount = sorted(classCount.items(), key=operator.itemgetter(0), reverse=True)
print(sortedClassCount)

[(3, 9), (1, 12), (0, 10)]
 

3.tile()

from numpy import *
a=[[1,2,3],[4,5,6]]
b=tile(a,(2,1))
print(b)

[[1 2 3]
 [4 5 6]
 [1 2 3]
 [4 5 6]]

4.get()               

https://blog.csdn.net/weixin_38705903/article/details/79231551 

5.strip()&split()

https://www.cnblogs.com/yyxayz/p/4034299.html

6.readlines&readline

https://www.jb51.net/article/119907.htm