代码:
'''
用户与程序交互:
input( )输入
print()输出
username=input('请输入提示信息')
'''
username=input('请输入用户名:')
print(username)
password = input('请输入密码:')
print(password)
# 如果
# username == 'tank ' True
# and: 左右两边的条件都为了True才为True,否则为False
# password == '123' True
# if 条件判断:如果条件判断 == True,执行if下的代码
if username =='tank' and password == '123':
# False and True ---》 False
print('登录成功')
else:
print('登陆失败')
# 占位符: %s
str1 = '很帅'
print('tank%s' % (str1,)) # tank很帅
str2 = '信念与我同在,我将无坚不摧'
print('自信养成记1: %s' % (str2, ))
price1 = input('请输入该用户当月扣费月租')
all = input('请输入该用户当前余额: ')
print('亲爱的移动用户,您当前月租为[%s]元,账户余额为[%s]元 '
% (price1,all))
# - 算数运算符
print(1+1) # 2
n1 = 1
# n1 =n1 + 1 # n1 += 1
# print(n1) # 2
n1 += 1
# 赋值运算符: -=
print(10 - 1) # 9
# *=
print(12 * 12) # 144
print(11 / 3) # 3.666...
print(11 // 3) # 3
print(11 % 3) # 2
# 比较运算符
print(1 == 2) # False
print(1 >2) # False
print(1 < 2) # True
print(1 >=2 ) # False
print(1 <= 2) # Ture
# is:比较两个变量的id是否相等
x = 10
print(id(x) == id(x) ) # True
print(x is x) # True
#逻辑运算符
# and: 左右两边的条件都为了True才为True,否则为False
print(x == 1 and x == 10) # False
print(x == 10 and x == 10) # True
# or:判断两边的条件是否成立,其1成立则为Ture
print(x == 10 or x == 1) # True
# not:取反
print(x == 10) # True
print(not x == 10) # False
# no-->and-->or
# True or Fslse
print(not x == 1 or x == 10 and x == 20) # True
# 链式赋值
n = 10
y = n
z = y
print(n,y,z)
n = y = z = 10
print(n,y,z)
#交叉赋值
x = 10
y = 20
# x与y的值互换
# x = 20 y = 10
z = x # 10
x = y # 20
y = z # 10
x = 10
y = 20
# 10, 20 = y = 10, x=20
x, y = y, x
print(x,y) # 20 10
# 解压缩赋值
# 0 1 2
list1 = [1,2,3]
x = list1[0]
y = list1[1]
z = list1[2]
print(x,y,z) # 1 2 3
x,y,z = list1
print(x,y,z) # 1 2 3
#猜测游戏: 猜测用户输入的字符是否是9527
number=9527
guess=('请输入猜测数字')
print(guess)
print(type(guess)) # str
#把字符串类型转为整型
guess=int(guess)
print(type(guess)) # int
if guess==number:
print('猜对了!')
elif guess<number:
print('猜小了!')
else:
print('猜大了!')
'''
while循环:
语法:
while 判断条件:
# 若条件成立则"循环"执行以下代码
print('111')
break:结束本层循环
'''
import time
while True:
print(11111)
time.sleep(1)
break
# 猜字符游戏:猜测用户输入的字符是否是9527,限制只能猜3次
number = 9527
init = 1 # 1 2 3 4
while True:
# 若int大于3结束循环
if init > 3:
print('猜错3次了,gun吧!')
break
guess= input('请输入猜测数字:')
guess = int(guess)
if guess == number:
print('猜对了!')
break
elif guess < number:
print('猜小了!')
else:
print('猜大了!')
# 若没有退出循环证明猜错了,init + 1
init += 1
list1 = [1,2,3,4,5]
# list1_len = len(list1) # 5
#
#white list1_len > 0:
# list1_len -= 1
# # print(list1_len) # 4 3 2 1 0
# print(list1{list1_len})
# 依次循坏取出list1中的每一个值
for x in list1:
print(x)
笔记:
1.可变与不可变
当数据修改时,id不变称之为可变类型,否则称之为不可变类型。
2. - 流程控制
对流程的控制,控制某些事情的发生
-if分支判断:
语法:
if判断条件:
#条件若成立执行
print('条件成立')
#若if条件成立,则执行此处
elif判断条件:
print(另一个条件成立)
#若if与elif条件不成立,则执行此处
else:
# 若条件不成立则执行
print("条件不成立")