结构

if else

num = input("输入一个数字：")
if int(num)<10:
	print(num)
else:
	print('大于10')

score = int(input('输入分数:'))
grade = ''
if score < 90 :
    grade = 'D'
elif score < 120 :
    grade = 'C'
elif score < 130 :
    grade = 'B'
else:
    grade = 'A'
print('分数是{0}，等级{1}'.format(score,grade))

三元条件运算符

num = int(input('输入年龄:'))
print('成年人' if num>18 else '未成年' )

选择结构嵌套+While循环

while 1:
    score = int(input('输入分数:'))
    grade = ''
    if score > 150 or score <0:
        print('成绩输入有误!')
    else:
        if score < 90 :
            grade = 'D'
        elif score < 120 :
            grade = 'C'
        elif score < 130 :
            grade = 'B'
        else:
            grade = 'A'
        print('分数是{0}，等级{1}'.format(score,grade))

for循环与可迭代对象

• for循环

• 可迭代对象

#嵌套for循环实现乘法表
for i in range(1,10):
    for j in range(1,i+1):
        print('{0}*{1}={2}'.format(i,j,i*j),end='\t')
    print()

break 语句

continue 语句