if语句

1. 实例：

home = ['aa','bb','cc','dd']
for homes in home:
    if homes ==  'aa':
        print(homes.title())
    else:
        print(homes.upper())

输出结果为 Aa BB CC DD

2. 关键词 in：判断列表是否包含特定值

home = ['aa','bb','cc','dd']
'aa' in home

结果为 True

'ss' in home 

结果为 False

3. if-else

age = 17
if age>=18:
   print('nice')
else:
   print('nono')

4. if-elif-else

age = 12
if age<4:
  print('small')
elif age>18:
  print('big')
else:
  print('nice')