python 的技巧

pi = 0
n = 100
for k in range(n):
    pi+=1/pow(16,k)*(\  #一行不够写或不易读时用\,则多行与一行一样
        4/(8*k+1)-2/(8*k+4)-\
        1/(8*k+5) -1/(8*k+6))
print("圆周率: {}".format(pi))

 输入

a,b = input().split()
a+=b
print(a)
6 -5
6-5
a,b,c=map(eval,input().split())
a+=b
print(a,c)
0.3 1.5 6
1.8 6

 

循环

list_of_lists = [range(4), range(7)]
flattened_list = []

#flatten the lis
for x in list_of_lists:
    for y in x:
        flattened_list.append(y)

0
1
2
3
0
1
2
3
4
5
6

list = [range(4),range(7)]
flattened = [y for x in list for y in x]
print(flattened)

[0, 1, 2, 3, 0, 1, 2, 3, 4, 5, 6]