with open('test.txt','r',encoding="UTF-8") as f:print(f.read())          #读取文件全部内容
with open('test.txt', 'r', encoding="UTF-8") as f:print(f.readlines())  # 读取文件每行内容，存入列表
with open('test.txt', 'r', encoding="UTF-8") as f:print(f.readline())  # 读取文件一行内容
with open('test.txt','rb') as f:print(f.read())          #字节读取模式读取文件全部内容

with open('test1.txt','w',encoding="UTF-8") as f:f.write("hello world!\n")  #文本模式，需添加换行符
with open('test1.txt','w',encoding="UTF-8") as f:f.writelines(["hello\n","world\n"])  #文本模式，需添加换行符
with open('test1.txt','wb') as f:f.write("hello world".encode("utf-8"))  #b模式需对字符先编码
with open("test1.txt",'wb') as f:f.writelines(["hello\n".encode("utf-8"),"world\n".encode("utf-8")]) #b模式需对字符串手动编码

import time
f = open("test1.txt",'w',encoding="UTF-8") #b模式没有encoding
print(f.writable())   #文件是否看可写
print(f.readable())   #文件是否可读
f.write("aa")
f.flush()    #立刻将文件内容从内容刷入硬盘
time.sleep(5)
f.close()       #文件关闭，无flush时，关闭文件内容才刷入硬盘

with open("test.txt",'r',encoding="UTF-8") as f:f.seek(4,0)   #第一个参数表示移动的相对位置，第二个参数为0表示移动到文件开头，1表示就在当前位置，2表示移动到文件末尾print(f.read())print(f.tell())  #返回光标当前位置，执行为read()后为文件末尾
#truncate为截断文件，文件必须可写，不可使用w或w+模式，会清空文件，建议使用r+或者a或a+模式
with open("test.txt",'r+',encoding="UTF-8") as f:f.truncate(7)    #截取前7个字节的内容。

import os
with open("test.txt",'r') as read_f,open(".test.txt.swap",'w') as write_f:data = read_f.read()data = data.replace("xxx","eee")   #字符不可变，需重新赋值给datawrite_f.write(data)
os.remove("test.txt")
os.rename(".test.txt.swap","test.txt")

import os
with open("test.txt",'r') as read_f,open(".test.txt.swap",'w') as write_f:for line in read_f:if "xxx" in line:line = line.replace("xxx","eee")write_f.write(line)
os.remove("test.txt") os.rename(".test.txt.swap","test.txt")

#语法
def 函数名(参数1,参数2,参数3,...):'''注释'''函数体return 返回的值#函数名要能反映其意义

def func(*args,**kwargs):print(args,kwargs)
func(3,4,5,66,a=33,b="asf",c=222)   #前面的位置实参被args以元组方式接收，后面的关键字实参被kwargs以字典方式接收

def func(x,y,*args,a=1,b,**kwargs):print(x,y)print(args)print(a)print(b)print(kwargs) func(1,2,3,4,5,b=3,c=4,d=5)

def func1():print("from func1")return func2      #返回func2
def func2():print("from func2")
list = []
list.append(func1())  #返回func2作为列表元素
list[0]()         #执行func2

def func1():print("from func1")def func2():print("from func2")def func3():print("from func3") func3() func2() func1()

#优先在func()局部名称空间中找max，如果没有在全局找，如果还没有在返回内置名称空间中的max
max = 3
def func():max = 1print(max)
func()

xxx=2222
yyy="dsfsf"
print(globals())
print(locals())   #全局作用域中调用locals()相当于调用globals()
def func():zzzzz=[1,2,3,4]print(locals())
print(globals())   #仅比前面的globals多了func函数名字，无func函数中定义的变量名字
func()

xxx = "abc"
def outter():def innner():print("inner",xxx)return innner
f = outter()
def bar(): x=123456 f() #f()实际上就是inner(),调用时局部作用域中无xxx，则去全局作用域中找，无法调用bar()中的xxx bar()

z =1
def outter():x = 1y = 2def inner():print(x,y)return inner
f =outter() print(f.__closure__[0].cell_contents) #返回闭包函数中第一个引用外部名字的值

#普通的调用方法，每次执行时需传入参数。
import requests
def get(url):response = requests.get(url)if response.status_code == 200:print(len(response.text))
get("https://www.baidu.com") #使用闭包函数后，参数由外部函数传入，方便执行 import requests def outter(url) def get(): response = requests.get(url) if response.status_code == 200: print(len(response.text)) return get baidu = outter("https://www.baidu.com") baidu()

import time
def index():time.sleep(3)print("welcome to index")def outter(func):def inner(): start = time.time() func() stop = time.time() print("run time is %s"%(stop-start)) return inner index = outter(index) index()

import time
def index(name):time.sleep(3)print("welcome %s to index" % name)
def outter(func):def inner(*args,**kwargs): start = time.time() func(*args,**kwargs) stop = time.time() print("run time is %s" %(stop-start)) return inner index = outter(index) index("xxx")

def auth(driver='file'):def auth2(func):def wrapper(*args,**kwargs):name = input("input user:")password = input("input password")if driver == "file": if name=="xxx" and password=="123": print("login success") return func(*args,**kwargs) elif driver == "ldap": print("ldap") return wrapper return auth2 @auth(driver="file") def foo(name): print("welcome "+name) foo("xxx")

import time
def outter(func):def inner(*args,**kwargs):start = time.time()func(*args,**kwargs)stop = time.time() print("run time is %s" %(stop-start)) return inner @outter #相当于index=outter(index),装饰器函数必须在被修饰函数上方定义 def index(name): time.sleep(3) print("welcome %s to index" % name) #index = outter(index) index("xxx")

from functools import wrapsdef deco(func):@wraps(func) #将传入被装饰函数的信息赋给内层函数，入帮助文档等。def wrapper(*args,**kwargs):return(func(*args,**kwargs))return wrapper
@deco
def index(): "原始index的帮助文档" print("from index") print(index.__doc__)