Python学习（四） 结构------循环、分支

一、循环
for循环使用实例

#写for循环的时候注意缩进
magicians = ['alice', 'david', 'carolina']
for magician in magicians:
    print(magician)

while循环使用实例

sandwich_orders = ['he','chong','yang']
finished_sandwiches = []
while sandwich_orders:
    finished_sandwiches.append(sandwich_orders.pop())
    print("i made you tuna sandwich")
print(finished_sandwiches)

二、分支
if语句的使用实例
在比较运算符的两边添加一个空格是良好的编程习惯

num = [1,2,3,4,5,6,7,8,9]
for i in num:
    if(i == 1):
        print("1st")
    elif(i == 2):
        print("2nd")
    elif(i == 3):
        print("3rd")
    else:
        print(str(i)+"th")