Python基础

1 #循环列表
2 values = [10,20,4,50.31]
3 squres = []
4 for x in values:
5     squres.append(x)
6 print(squres)

[10, 20, 4, 50.31]

#列表推导式
values = [10,20,4,50.31]
squres = [x for x in values]
print(squres)

[10, 20, 4, 50.31]

1 #推导式中加入条件进行筛选
2 values = [10,20,4,50.31]
3 squres = [x**2 for x in values if x<=12]
4 squres

[100, 16]

#推导式生成集合和字典
values = [10,20,4,50.31]
squres_set = {x**2 for x in values if x<=12}
squres_dict = {x:x**2 for x in values}
print(squres_set)
squres_dict

{16, 100}

{4: 16, 10: 100, 20: 400, 50.31: 2531.0961}

#求和表达式
values = [10,20,4,50.31]
sum(x**2 for x in values)

3047.0961