编辑代码

# coding:utf-8
#JSRUN引擎2.0，支持多达30种语言在线运行，全仿真在线交互输入输出。 
print("Hello world!   -  python.jsrun.net .")
a = [1, 2, 3]
b = 2
for i in range(len(a)):
    new_list = []
    new_list.append(b * int(a[i]))
print(new_list)

new_list = []
a = [1, 2, 3]
new_list = new_list + a + a
print(new_list)

a = [1, 2, 3]
i = 1
b = 3
new_list = []
while i <= b:
    new_list += a
    i += 1
print(new_list)