算术运算符与赋值运算符
#1. 算术运算 # print(10 / 3) # print(10 // 3) # print(10 ** 2) #2. 赋值运算 # 增量赋值 # age=18 # age+=1#age=age + 1 # print(age) # age=18 # age/=3 #age=age/3 # print(type(age)) # age**=2 #age=age**2 # 交叉赋值 # x=10 # y=20 # # # temp=x # # x=y # # y=temp # x,y=y,x # print(x,y) # 链式赋值 # x=10 # y=x # z=y # x=y=z=10 # # print(id(x)) # print(id(y)) # print(id(z)) # 解压赋值 l=[1.2,2.2,3.3,4.4,5.5] # a=l[0] # b=l[1] # c=l[2] # d=l[3] # e=l[4] # a,b,c,d,e=l # a,b,c,d,e,f=l # a,b,c,d=l # print(a,b,c,d,e) # l=[1.2,2.2,3.3,4.4,5.5] # a,b,*_=l # print(a,b) # a,*_,b=l # print(a,b) # *_,a,b=l # print(a,b)
流程控制之if判断
'''
语法1：
if 条件:
代码1
代码2
代码3
...
'''
# age_of_bk=30
# print('start.....')
#
# inp_age=input('>>>: ') #inp_age='18'
# inp_age=int(inp_age)
# if inp_age == age_of_bk:
# print('猜对了')
#
# print('end.....')
'''
语法2：
if 条件:
代码1
代码2
代码3
...
else:
代码1
代码2
代码3
...
'''
# age=38
# gender='male'
# is_beautiful=True
#
# if age >= 18 and age <= 25 and gender == 'female' and is_beautiful:
# print('开始表白。。。。')
#
# else:
# print('阿姨好')
#
'''
语法3：
if 条件1:
代码1
代码2
代码3
...
elif 条件2:
代码1
代码2
代码3
...
elif 条件3:
代码1
代码2
代码3
...
elif 条件4:
代码1
代码2
代码3
...
else:
代码1
代码2
代码3
...
'''
'''
如果：
成绩>=90，那么：优秀
如果成绩>=80且<90,那么：良好
如果成绩>=70且<80,那么：普通
其他情况：很差
'''
# score=input('your score>>: ')
# score=int(score)
# if score >=90:
# print('优秀')
# elif score >=80:
# print('良好')
# elif score >=70:
# print('普通')
# else:
# print('很差')
# if 条件1:
# 代码1
# 代码2
# 代码3
# if 条件2:
# 代码1
# 代码2
# 代码3
'''
语法4：
if 条件1:
if 条件2:
代码1
代码2
代码3
...
代码2
代码3
'''
age=18
gender='female'
is_beautiful=True
is_successful=True
if age >= 18 and age <= 25 and gender == 'female' and is_beautiful:
print('开始表白。。。。')
if is_successful:
print('在一起')
else:
print('我逗你玩呢。。。')
else:
print('阿姨好')
流程控制之while循环
#1. while循环：条件循环
# I: 基本语法
# while 条件:
# 代码1
# 代码2
# 代码3
# ...
# 示范
# name_of_bk='egon'
# pwd_of_bk='123'
#
# tag=True
# while tag:
# inp_name=input('your name>>: ')
# inp_pwd=input('your password>>: ')
# if inp_name == name_of_bk and inp_pwd == pwd_of_bk:
# print('login successful')
# tag=False
# else:
# print('username or password error')
#
# print('other code...')
# II: while+break:break代表结束本层循环
# 示范：
# while True:
# print(1)
# break
# print(2)
# print(3)
# name_of_bk='egon'
# pwd_of_bk='123'
#
# while True:
# inp_name=input('your name>>: ')
# inp_pwd=input('your password>>: ')
# if inp_name == name_of_bk and inp_pwd == pwd_of_bk:
# print('login successful')
# break
# else:
# print('username or password error')
#
# print('other code......')
# III: while + continue: continue代表结束本次循环，直接进入下一次
# 示范
# count=1
# while count < 6:
# if count == 3:
# count+=1
# continue
# print(count)
# count+=1
# 输错三次退出
# name_of_bk='egon'
# pwd_of_bk='123'
#
# count=0
# while True:
# if count == 3:
# print('输错的次数过多。。。')
# break
# inp_name=input('your name>>: ')
# inp_pwd=input('your password>>: ')
# if inp_name == name_of_bk and inp_pwd == pwd_of_bk:
# print('login successful')
# break
# else:
# print('username or password error')
# count+=1 #count=3 输错3次
# IV:while + else
# count=0
# while True:
# if count == 10:
# break
# print(count)
# count+=1
#
# else:
# print("else的子代块只有在while循环没有被break打断的情况下才会执行")
# count=0
# while count <= 10:
# print(count)
# count+=1
#
# else:
# print("else的子代块只有在while循环没有被break打断的情况下才会执行")
name_of_bk='egon'
pwd_of_bk='123'
count=0
tag=True
while tag:
if count == 3:
print('输错的次数过多。。。')
break
inp_name=input('your name>>: ')
inp_pwd=input('your password>>: ')
if inp_name == name_of_bk and inp_pwd == pwd_of_bk:
print('login successful')
while tag:
print("""
0 退出
1 购物
2 支付
3 查看购物
""")
cmd=input('>>>: ')
if cmd == '0':
tag=False
continue
if cmd == '1':
print('购物。。。。。。。')
elif cmd == '2':
print('支付。。。。。')
elif cmd == '3':
print('查看购物车')
else:
print('输入错误的指令')
else:
print('username or password error')
count+=1 #count=3 输错3次
#2. for循环