1、if..elif..else
age = 12 if age <4: price = 0 elif age <18: price = 5 else: price = 10 print("coast:%d" % price) >>>coast:5
2、if...elif没有else语句
age = 12 if age<4: price = 0 elif age <18: price = 5 elif age >65: price = 5 print ("coast:%d" % price) >>>coast:5
else语句可以不出现在if语句中,elif语句中,当年龄超过65岁,价格标位5
这样比else代码更清晰;else只要不满足if或elif中的条件测试,代码就会执行,
这样可能会引入无效或恶意的数据,多考虑用多个elif来代替else语句
3、if if if语句
cars = ["audi",'baojun',"zotype"] if "audi" in cars: print('add audi') if "dongfeng" in cars: print('add dongfeng') if "baojun" in cars: print('add baojun') print('\n Finish choose car end!') >>>add audi add baojun如果只想执行一个代码块,就用if...elif...else结构 ,如果需要使用到多个代码块需要使用上方独立的if语句