条件判断

age = 6
if age>=18:
    print('Your age is ',age)
    print('adult')
elif age>=6:
    print('Your age is ',age)
    print('teenager')
else:
    print('kid')

#只要x是非零数值、非空字符串、非空list等，就判断为True，否则为False。
x1 = 1
if x1:
    print('Good_1')
else:
    print('bad_1')

x2 = 'a'
if x2:
    print('Good_2')
else:
    print('bad_2')

x3 =[1,2]
if x3:
    print('Good_3')
else:
    print('bad_3')

x4 = []
if x4:
    print('Good_4')
else:
    print('bad_4')

x5 = 0
if x5:
    print('Good_5')
else:
    print('Bad_5')

x6 = ''
if x6:
    print('Good_6')
else:
    print('Bad_6')

x7 = ()
if x7:
    print('Good_7')
else:
    print('Bad_7')


# #input()
# birth = int(input('Enter your birth:'))
# # birth = input('Enter your birth:')  #TypeError: '>' not supported between instances of 'str' and 'int'
# if birth>2000:
#     print('00后')
# else:
#     print('00前')
'''
小明身高1.75，体重80.5kg。请根据BMI公式（体重除以身高的平方）帮小明计算他的BMI指数，并根据BMI指数：

    低于18.5：过轻
    18.5-25：正常
    25-28：过重
    28-32：肥胖
    高于32：严重肥胖

用if-elif判断并打印结果：
'''
height = float(input('Enter your height: '))
weight = float(input('Enter your weight: '))
BMI = weight/(height*height)
if BMI<18.5:
    print('过轻')
if 18.5<=BMI<25:
    print('正常')
if 25<=BMI<28:
    print('过重')
if 28<=BMI<32:
    print('肥胖')
if BMI>=32:
    print('严重肥胖')

    # 低于18.5：过轻
    # 18.5-25：正常
    # 25-28：过重
    # 28-32：肥胖
    # 高于32：严重肥胖