python语句

基本逻辑运算符（if ...elif...else）(0,False,None为假)

flag = False
name = 'luren'
if name == 'python':         # 判断变量否为'python'
    flag = True          # 条件成立时设置标志为真
    print('welcome boss')    # 并输出欢迎信息
else:
    print(name)              # 条件不成立时输出变量名称

 1 num = 5     
 2 if num == 3:            # 判断num的值
 3     print('boss')        
 4 elif num == 2:
 5     print('user')
 6 elif num == 1:
 7     print('worker')
 8 elif num < 0:           # 值小于零时输出
 9     print('error')
10 else:
11     print('roadman')     # 条件均不成立时输出

 1 num = 9
 2 if num >= 0 and num <= 10:    # 判断值是否在0~10之间
 3     print('hello')
 4 # 输出结果: hello
 5  
 6 num = 10
 7 if num < 0 or num > 10:    # 判断值是否在小于0或大于10
 8     print('hello')
 9 else:
10     print('undefine')
11 # 输出结果: undefine
12  
13 num = 8
14 # 判断值是否在0~5或者10~15之间
15 if (num >= 0 and num <= 5) or (num >= 10 and num <= 15):    
16     print('hello')
17 else:
18     print('undefine')
19 # 输出结果: undefine

age = 16
high = 170
success = True

if age:
    print('ok')
else:
    print('不OK')

if age > 17:
    if success:
        print('咱们结婚吧！')
    else:
        print('去他妈的爱情！')
elif high > 160:
    print('你好高')
else:
    print('不表白')

 score=input('>>: ')
 > 90:优秀
 80 < 90 :良好
 >=60 <80 :合格
 <60:滚犊子


 score = int(input('请输入你的成绩:'))
 if score > 90:
     print('优秀')
 elif score > 80 and score <= 90:
     print('良好')
 elif score >=60 and score < 80:
     print('合格')
 else:
     print('滚犊子')