1、变量的三大类型
import time
list1 = ['tank', 'jason']
# print('18岁的tank,是真的。')
# type
print(type(list1))
# id
print(id(list1))
# 4648825800
# 4620657608
time.sleep(5)
print('程序结束,list1被销毁')
# 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。(默写)
# 可变
list1 = ['tank', 'jason']
print('list1修改前ID:', id(list1))
list1.append('徐峰') # ['tank', 'jason'].append(徐峰)
print(list1)
print('list1修改后ID:', id(list1))
# 不可变:元组
tuple1 = (1, 2, 3)
print(id(tuple1))
print(type(tuple1))
tuple1 = (2, 3, 4)
print(id(tuple1))
2、用户与程序交互
'''
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('登陆成功')
else:
print('登录失败')
3、格式化输出
# 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,您当月月租为[%s]元,账户余额为[%s]元!' % (price1,all))
4、基本运算符
# 算术运算符
print(1 + 1)
n1 = 1
# n1 = n1 + 1 # n1 += 1
# print(n1)
n1 += 1
# 赋值运算符:-=
print(10 - 1)
# *=
print(12 * 12)
print(11 / 3)
print(11 // 3)
print(11 % 3)
# 比较运算符
print(1 == 2)
print(1 > 2)
print(1 < 2)
print(1 >= 2)
print(1 <= 2)
# is:比较两个变量的id是否相等
x = 10
print(id(x) == id(x))
print(x is x)
# 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)
print(x == 10 and x == 10)
# or:判断两边的条件是否成立,其1成立则为True
print(x == 10 or x == 1)
# not:取反
print(x == 10)
print(not x == 10)
# no-->and-->or
# True or False
print(not x == 1 or x == 10 and x == 20)
# 链式赋值
n = 10
y = n
z = y
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)
# 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)
x, y, z = list1
print(x, y, z)
5、流程控制
'''
if 分支
'''
# 猜字符游戏:猜测用户输入的字符是否是9527。
number = 9527
guess = input('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init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
# 0 1 2 3 4
# list1 = [1, 2, 3, 4, 5]
'''
需求:
循环取出列表list1的每一个值。
for循环:
for x in 需要循环的值:
for x in list1: # x=1, x=2, x=3, x=4, x=5
print(x)
'''
list1 = [1, 2, 3, 4, 5]
# list1_len = len(list) # 5
# while list1_len > 0:
# list1_len -= 1
# # print(list1_len) # 4 3 2 1 0
# print(list1[list1_len])
# 依次循环取出list1中的每一个值
for x in list1:
print(x)