age = 18
age = int('18')
+ - * / % // **
salary = 3.2
salary = float('3.2')
+ - * / % // **
name = 'nick'
name = "nick"
name = '''
nick
nick
'''
name = """
nick
nick
"""
name = "'nick'"
name = '"nick"'
friends_list = ['longzeluola','canglaoshi','qiaobenai','nick']
lis = list('abcd')
friends_tuple = ('longzeluola','canglaoshi','qiaobenai','nick')
tup = tuple('abcd')
nick_info_dict = {
'name':'nick',
'height':180,
'weight':140,
'hobby_list':['read','run','music','fishing','programming','coding','debugging']
}
for k,v in nick_info_dict.items():
print(k,v)
s = set()
s = {1,2,3,4,5,1}
==
一个值 | 多个值 |
---|---|
整型/浮点型/字符串 | 列表/元祖/字典/集合/ |
有序 | 无序 |
---|---|
字符串/列表/元祖 | 字典/集合 |
可变 | 不可变 |
---|---|
列表/字典/集合 | 整型/浮点型/字符串 |
l1 = ['a','b','c',['d','e','f']]
l2 = l1
l1.append('g')
print(l1) # ['a','b','c',['d','e','f'],'g']
print(l2) # ['a','b','c',['d','e','f'],'g']
如果l2是l1的拷贝对象,则l1内部的任何数据类型的元素变化,则l2内部的元素也会跟着改变,因为可变类型值变id不变
import copy
l1 = ['a','b','c',['d','e','f']]
l2 = copy.copy(l1)
l1.append('g')
print(l1) # ['a','b','c',['d','e','f'],'g']
print(l2) # ['a','b','c',['d','e','f']]
l1[3].append('g')
print(l1) # ['a','b','c',['d','e','f','g'],'g']
print(l2) # ['a','b','c',['d','e','f','g']]
如果l2是l1的浅拷贝对象,则l1内的不可变元素发生了改变,l2不变;如果l1内的可变元素发生了改变,则l2会跟着改变
import copy
l1 = ['a','b','c',['d','e','f']]
l2 = copy.deepcopy(l1)
l1.append('g')
print(l1) # ['a','b','c',['d','e','f'],'g']
print(l2) # ['a','b','c',['d','e','f']]
l1[3].append('g')
print(l1) # ['a','b','c',['d','e','f','g'],'g']
print(l2) # ['a','b','c',['d','e','f']]
如果l2是l1的深拷贝对象,则l1内的不可变元素发生了改变,l2不变;如果l1内的可变元素发生了改变,l2也不会变,即l2永远不会因为l1的变化而变化
age = 18 # 答案
count = 0 # 游戏次数控制
prize_dict = {
0:'布娃娃',
1:'变形金刚',
2:'奥特曼',
3:'<Python从入门到放弃>'
}
# 核心代码
while count < 3:
inp_age = input('请输入你的年龄>>>').strip() # 与用户交互
# 判断用户是否骚扰
if not inp_age.isdigit():
print('傻逼,你的年龄输错了')
continue
inp_age_int = int(inp_age)
# 核心逻辑,判断年龄
if inp_age_int == age:
print('猜对了')
print(prize_dict) # 打印奖品
# 获取两次奖品
for i in range(2):
prize_choice = input('请输入你想要的奖品,如果不想要,则输入"n"退出!!!').strip() # 与用户交互获取奖品
# 判断是否需要奖品
if prize_choice != 'n':
print(f'恭喜你获得奖品: {prize_dict[int(prize_choice)]}')
else:
break
break
elif inp_age_int < age:
print('猜小了')
else:
print('猜大了')
count += 1 # 成功玩一次游戏
if count != 3:
continue
again_choice = input('是否继续游戏,继续请输入"Y",否则任意键直接退出.').strip() # 交互是否再一次
# 判断是否继续
if again_choice == 'Y':
count = 0
+ - * / // % **
+ - * / // % **
可变 | 不可变 |
---|---|
列表,字典,集合 | 字符串,整形,浮点型 |
有序 | 无序 |
---|---|
字符串,列表,元组 | 字典,集合 |
存一个值 | 存多个值 |
---|---|
整型,浮点型,字符串 | 列表,集合,字典,元组 |
l1= [1,1]
l2 = l1
l1 = [1,2,[1,2]]
import copy
l2 = copy.copy(l1)
l1 = [1,2,3,[2,3]]
import copy
l2 = copy.deepcopy(l1)
当python3解释器启动,并生成变量时,会以unicode的形式把变量读入内存,当我们使用print方法时,print会自动按照终端的字符编码 编码unicode形式的变量
生成变量时以unicode丢入内存,终端时gbk,还是utf8,这终端都可以识别。 生成变量时以utf8丢入内存,终端为utf8,可以,但是终端为gbk,不可以了。==错误==
with open(文件名,打开模式,编码格式) as f:
f.操作命令
with open(文件一),open(文件二),open(文件三)……
with open('a.txt','r',encoding='utf8') as fr, open('a_swap.txt','w',encoding='utf8') as fw:
data = fr.read()
# 做一些处理之后
fw.write(data)
fw.flush()
import os
os.remove('a.txt')
os.rename('a_swap.txt','a.txt')
def 函数名():
代码块
def f1():
return 2
f1()
f = f1()
import random
import time
with open('0531总复习.md','r',encodint='utf8') as fr:
for i in range(50):
fr.read(random.randint(1,300))
time.sleep(30)
def f1():
pass
# 1.引用
f = f1
# 2.当作返回值
def f2():
return f1
# 3. 当作参数传入
def f3(func):
func()
f3(f1)
# 4. 作为容器元素
lis = [1,2,3,[2,3],f1,f2,f3]
def f1():
def f2():
pass
作用域: 全局的变量和局部的变量没有任何关系,即使两者中有同一名字的变量,同意名字的变量之间进行任何操作都不会影响对方
x = 10
def f1():
x = 2
print(x) # 2
f1()
print(x) # 10
lis = [1]
def f1():
lis[0] = 2
f1()
print(lis) # [2]
def f1(x):
def f2():
print(x)
return f2
f = f1(5) # f-->f2,x=5
f() # f()-->f2(),x=5 # 5
f() # 5
f3 = f1(3) # f-->f2,x=3
f3() # f()-->f2(),x=3 # 3
f3() # 3
def deco(func):
def wrapper(*args,**kwargs): # 赋值后的time_sleep
res = func(*args,**kwargs) # 真正的time_sleep
return res
return wrapper
@deco # time_sleep(赋值后的) = deco(time_sleep(真正的))
def time_sleep(name):
print(name)
return 123
is_login_dict = {'username': None}
def login_deco(func):
def wrapper(*args, **kwargs): # 赋值后的time_sleep
if not is_login_dict['username']:
username = input('请输入你的用户名》》》').strip()
if username != 'fanping':
print('非法登录')
return
is_login_dict['username'] = username
res = func(*args, **kwargs) # 真正的time_sleep
return res
else:
res = func(*args, **kwargs) # 真正的time_sleep
return res
return wrapper
@login_deco
def shopping():
print('from shopping')
@login_deco
def withdraw():
print('from withdraw')
is_login_dict = {'username': None}
def auth(origin):
def login_deco(func):
def wrapper(*args, **kwargs): # 赋值后的time_sleep
if origin == 'file':
if not is_login_dict['username']:
username = input('请输入你的用户名》》》').strip()
if username != 'fanping':
print('非法登录')
return
is_login_dict['username'] = username
res = func(*args, **kwargs) # 真正的time_sleep
return res
else:
res = func(*args, **kwargs) # 真正的time_sleep
return res
elif origin == 'mongodb':
print('非法登录')
else:
print('dsb')
return wrapper
return login_deco
# f = origin('file') # login_deco
# shopping = f(shopping)
# shopping()
@auth('file')
def shopping():
print('from shopping')
@auth('mongodb')
def withdraw():
print('from withdraw')