python中if语句的使用

1.对体重标准的判断

#coding:utf-8

height=170
weight=65
#weight=height-105
if weight<height-105:
print '您偏瘦！注意补充营养'
elif weight>height-105:
print '您偏胖！注意锻炼身体'
else:
print '完美'
print '您的健康体重应该是：%d' %weight

2 对lily和Tom年龄的比较

#coding:utf-8
#驼峰命名
age_of_lily=10
AgeOfTom=12
if age_of_lily<AgeOfTom: #语句中的‘：’不能省略
print 'lily is old' #print语句前面有空格,用Tab键打空
elif age_of_lily>AgeOfTom:
print 'tom is old'
elif age_of_lily==AgeOfTom:
print 'they are twins'

else:
print 'error!'

3 对公司员工实发工资的计算

这里有输出print '实发工资：%.2f' %ssal

%.2f是保留小数点后两位

#coding:utf-8
sal=8000#所发工资
baox=1100#保险
saltax=sal-baox-3500 #应纳税所得额
if saltax<1500:#注意冒号
tax=(sal-baox-3500)*0.03 #缴费
ssal=sal-baox-tax #真实工资
print '实发工资：%.2f' %ssal
elif 1500<saltax<4500:
tax=(sal-baox-3500)*0.1-105
ssal=sal-baox-tax
print '应缴费：%d'%tax
print '实发工资：%.2d'%ssal
elif 4500<saltax<9000:
tax=(sal-baox-3500)*0.2
ssal=sal-baox-tax
print '应缴费：%d'%tax
print '实发工资：%d'%ssal
else:
print '不在范围内，请重新选择！'