解包：
# mag = "admin,123123" # print(mag.split(',')) # username,password = mag.split(',') # print(username) # print(password) l =[1,2,3] l2=(1,2,3) l3='abc' f, s, d = l #只要有下标的都可以这样取值 print(f, s, d) d = {"username":"admin","password":"123123"} print(d.items()) #把字典转成二维数组list #dict_items([('username', 'admin'), ('password', '123123')]) for k,v in d.items(): print(k) print(k,v)
文件操作：
#r+ w+ a+ #rb wb ab # b二进制模式 #rb+ wb+ ab+ #读写 写读 追加读模式 #1、r相关，文件不存在的时候报错FileNotFoundError，指针在最前面，覆盖最前面的 # 如果写的话要把指针移到最后面 #2、w相关，重新创建文件，清空文件内容 #3、a相关，读的话要移动指针f.seek(0)，不管怎么移动指针，追加时都在文件末尾追加 # 文件不存在会创建 #1、r+，不能写，文件不存在的时候报错FileNotFoundError #2、w+,不能读 #3、a+,不能读 # f = open('user.txt','r+') # f.writelines("n2") # f.flush()#刷新缓存区，让数据立刻写到磁盘上 # f.tell()#指针的位置 # result = f.read() # f.close() # print(result) # f = open('access.log','r+') # for line in f: #循环文件对象就是循环文件的每一行 # print(line) # f.close() #修改文件 # f = open(r'C:\Users\李家强\PycharmProjects') #r原字符,不需要转义 # f = open("user.txt",'a+',encoding="utf-8") # f.seek(0) # result = f.read() # result_new = result.replace("hello","你好") # f.seek(0) # f.truncate() #清空文件 # f.write(result_new) # f.close() import os f1 = open("user.txt",encoding='utf-8') f2 = open("user.txt.bak","w",encoding="utf-8") for line in f1:#循环文件对象就是循环文件的每一行 new_line = line.replace("周","周杰伦")#替换 f2.write(new_line)#写入新的 f1.close() f2.close() os.remove("user.txt")#删除 os.rename("user.txt.bak","user.txt")#改名成user.txt #自动关闭文件 with open("user.txt",encoding='utf-8') as f,open("user2.txt",encoding='utf-8') as f2: for line in f1: new_line = line.replace("周", "周杰伦") f2.write(new_line) os.remove("user.txt") os.rename("user2.txt", "user.txt")
json模块：
import json import pprint # python的数据类型转json: json.dumps # d = {"code":0,"msg":"操作成功","token":"xxxx"} # pprint.pprint(d) # json_str = json.dumps(d,ensure_ascii=False)#unicode显示中文 # pprint.pprint(json_str)#unicode # json的数据类型转python: json.loads # json_str = '{"code":0,"msg":"操作成功","token":"xxxx"}' # dic = json.loads(json_str) # pprint.pprint(dic) # with open("user.txt",encoding='utf-8') as f: # d = json.loads(f.read()) # print(d) d = {"code":0,"msg":"操作成功","token":"xxxx"} # with open("user.json",'w',encoding='utf-8') as f: # json_str = json.dumps(d,ensure_ascii=False,indent=4)#indent格式 # f.write(json_str) #load 自动读 不用写read with open("user.txt",encoding='utf-8') as f: result = json.load(f) print(result) #dump 自动写 不用write with open("user.txt",encoding='utf-8') as f: json.dump(d,f,ensure_ascii=False,indent=4)
监控日志练习：
import time FILE_NAME = 'access.log' point = 0 while True: ips = {} f = open(FILE_NAME,encoding='utf-8') f.seek(point) if point==0: #判断是否为第一次读取 f.read() else: for line in f: line = line.strip() if line: ip = line.split()[0] if ip in ips: ips[ip] +=1 else: ips[ip] = 1 point = f.tell() f.close() for ip,count in ips.items(): if count>=50: print("加入黑名单的ip是 %s" % ip) time.sleep(60)
函数：
#函数、方法 #提高代码复用，简化代码 #定义函数 # # 没有写return： 返回值none # def hello(): # print('hello') # #调用函数 ，才会执行 # # hello() # print(hello()) # return多个值,返回有值 # def welcome(name,age="13"): # return name,age # print("welcome %s,you are from %s"%(name,age)) # print(welcome("lee")) # print(welcome("li","14")) # return空,返回none # def test(): # return # print(test()) def op_file(filename,content=None): with open(filename,'a', encoding='utf-8') as f: f.seek() if content: f.write(content) else: result = f.read() return result
def is_float(s): s = str(s) if s.count('.') == 1: left, right = s.split('.') # [1,1]#-s.2 if left.isdigit() and right.isdigit(): return True elif left.startswith('-') and left.count('-') == 1 \ and left[1:].isdigit() and right.isdigit(): return True return False
函数参数：
def send_sms(*args):#可选参数，接受的是一个元祖 *args print(args) send_sms() send_sms(2) send_sms(2,3,4,5,6,'o') def send_sms(**kwargs):#关键字参数，接受的是一个字典 **kwargs print(kwargs) send_sms() send_sms(a = 2) send_sms(a=2,b=3,c=4,d=5,e=6,f='o')
全局变量：
# a = 100 # 全局变量 # def test(): # global a #global声明改的是全局变量a=1,写代码时少用全局变量 # a =1 # print(a) # # test() # print(a) # # def test(): # global a # a = 5 # # # def test1(): # c = a + 5 # return c # # test() # res = test1() # print(res) # 循环里 return==break
递归：
#函数自己调用自己，就是递归 # def test(): # number = input("请输入一个数字：").strip() # number = int(number) # if number %2 == 0: # print("输入正确") # return # test() # test() def replace(src,old,new): if old in src: return new.join(src.split(old)) return src a = 'abc,abc,sdgsd,' #[abc你好abc你好sdgsd你好] b = "123" c = "你好" result = replace(a,b,c) print(result)
