函数基础-练习
1 #1、写函数,,用户传入修改的文件名,与要修改的内容,执行函数,完成批了修改操作 2 # def modify_file(filename,old,new): 3 # import os 4 # with open(filename,'r',encoding='utf-8') as read_f, 5 # open('.bak.swap','w',encoding='utf-8') as write_f: 6 # for line in read_f: 7 # if old in line: 8 # line=line.replace(old,new) 9 # write_f.write(line) 10 # os.remove(filename) 11 # os.rename('.bak.swap',filename) 12 #2、写函数,计算传入字符串中【数字】、【字母】、【空格] 以及 【其他】的个数 13 # def check_str(msg): 14 # res={ 15 # 'al_num':0, 16 # 'spance_num':0, 17 # 'digit_num':0, 18 # 'others_num':0, 19 # } 20 # 21 # for s in msg: 22 # if s.isdigit(): 23 # res['al_num']+=1 24 # elif s.isspace(): 25 # res['spance_num']+=1 26 # elif s.isalpha(): 27 # res['digit_num']+=1 28 # else: 29 # res['others_num']+=1 30 # return res 31 # res=check_str('hello name:aSB passowrd:alex3714') 32 # print(res) 33 #3.判断用户传入的对象(字符串、列表、元组)长度是否大于5。 34 # def funcl(s,li,tup): 35 # s=len(s) 36 # i=len(li) 37 # o=len(tup) 38 # if s>5: 39 # print('yes') 40 # else: 41 # print('no') 42 # if i>5: 43 # print('yes') 44 # else: 45 # print('no') 46 # if o>5: 47 # print('yes') 48 # else: 49 # print('no') 50 # return(s,i,o) 51 # m=funcl('fdsfwefewwe',(34,45,56),[11,222,33]) 52 # print(m) 53 #4.检查传入列表的长度,如果大于2,那么仅保留前两个长度的内容,并将新内容返回给调用者 54 55 # def funcl(seq): 56 # if len(seq)>2: 57 # seq=seq[0:2] 58 # return sequh 59 # print(funcl([1,2,3,4])) 60 61 #5.检查获取传入列表或元组对象的所有奇数位索引对应的元素,并将其作为新列表返回给调用者 62 # def func1(seq): 63 # return seq[::2] 64 # print(func1([1,2,3,4,5,6])) 65 # 66 # def func2(dic): 67 # d={} 68 # for k,v in dic.items(): 69 # if len(v)>2: 70 # d[k]=v[0:2] 71 # return d 72 # print(func2({'k1':'werwerewr','k2':[1,2,3,4],'k3':('a','b','c')}))
1 # 6、写函数,检查字典的每一个value的长度,如果大于2,那么仅保留前两个长度的内容,并将新内容返回给调用者。 2 # dic = {"k1": "v1v1", "k2": [11,22,33,44]} 3 # PS:字典中的value只能是字符串或列表 4 # def func3(dic): 5 # d={} 6 # for k,v in dic.items(): 7 # if len(v) > 2: 8 # d[k]=v[0:2] 9 # return d 10 # print(func3({'k1':'abcdef','k2':[1,2,3,4],'k3':('a','b','c')}))
装饰器-练习
四:编写装饰器,为多个函数加上认证的功能(用户的账号密码来源于文件),要求登录成功一次,后续的函数都无需再输入用户名和密码 注意:从文件中读出字符串形式的字典,可以用eval('{"name":"egon","password":"123"}')转成字典格式 五:编写装饰器,为多个函数加上认证功能,要求登录成功一次,在超时时间内无需重复登录,超过了超时时间,则必须重新登录 六:编写下载网页内容的函数,要求功能是:用户传入一个url,函数返回下载页面的结果 七:为题目五编写装饰器,实现缓存网页内容的功能: 具体:实现下载的页面存放于文件中,如果文件内有值(文件大小不为0),就优先从文件中读取网页内容,否则,就去下载,然后存到文件中 扩展功能:用户可以选择缓存介质/缓存引擎,针对不同的url,缓存到不同的文件中 八:还记得我们用函数对象的概念,制作一个函数字典的操作吗,来来来,我们有更高大上的做法,在文件开头声明一个空字典,然后在每个函数前加上装饰器,完成自动添加到字典的操作 九 编写日志装饰器,实现功能如:一旦函数f1执行,则将消息2017-07-21 11:12:11 f1 run写入到日志文件中,日志文件路径可以指定 注意:时间格式的获取 import time time.strftime('%Y-%m-%d %X')
#题目四: db='db.txt' login_status={'user':None,'status':False} def auth(auth_type='file'): def auth2(func): def wrapper(*args,**kwargs): if login_status['user'] and login_status['status']: return func(*args,**kwargs) if auth_type == 'file': with open(db,encoding='utf-8') as f: dic=eval(f.read()) name=input('username: ').strip() password=input('password: ').strip() if name in dic and password == dic[name]: login_status['user']=name login_status['status']=True res=func(*args,**kwargs) return res else: print('username or password error') elif auth_type == 'sql': pass else: pass return wrapper return auth2 @auth() def index(): print('index') @auth(auth_type='file') def home(name): print('welcome %s to home' %name) # index() # home('egon') #题目五 import time,random user={'user':None,'login_time':None,'timeout':0.000003,} def timmer(func): def wrapper(*args,**kwargs): s1=time.time() res=func(*args,**kwargs) s2=time.time() print('%s' %(s2-s1)) return res return wrapper def auth(func): def wrapper(*args,**kwargs): if user['user']: timeout=time.time()-user['login_time'] if timeout < user['timeout']: return func(*args,**kwargs) name=input('name>>: ').strip() password=input('password>>: ').strip() if name == 'egon' and password == '123': user['user']=name user['login_time']=time.time() res=func(*args,**kwargs) return res return wrapper @auth def index(): time.sleep(random.randrange(3)) print('welcome to index') @auth def home(name): time.sleep(random.randrange(3)) print('welcome %s to home ' %name) index() home('egon') #题目六:略 #题目七:简单版本 import requests import os cache_file='cache.txt' def make_cache(func): def wrapper(*args,**kwargs): if not os.path.exists(cache_file): with open(cache_file,'w'):pass if os.path.getsize(cache_file): with open(cache_file,'r',encoding='utf-8') as f: res=f.read() else: res=func(*args,**kwargs) with open(cache_file,'w',encoding='utf-8') as f: f.write(res) return res return wrapper @make_cache def get(url): return requests.get(url).text # res=get('https://www.python.org') # print(res) #题目七:扩展版本 import requests,os,hashlib engine_settings={ 'file':{'dirname':'./db'}, 'mysql':{ 'host':'127.0.0.1', 'port':3306, 'user':'root', 'password':'123'}, 'redis':{ 'host':'127.0.0.1', 'port':6379, 'user':'root', 'password':'123'}, } def make_cache(engine='file'): if engine not in engine_settings: raise TypeError('egine not valid') def deco(func): def wrapper(url): if engine == 'file': m=hashlib.md5(url.encode('utf-8')) cache_filename=m.hexdigest() cache_filepath=r'%s/%s' %(engine_settings['file']['dirname'],cache_filename) if os.path.exists(cache_filepath) and os.path.getsize(cache_filepath): return open(cache_filepath,encoding='utf-8').read() res=func(url) with open(cache_filepath,'w',encoding='utf-8') as f: f.write(res) return res elif engine == 'mysql': pass elif engine == 'redis': pass else: pass return wrapper return deco @make_cache(engine='file') def get(url): return requests.get(url).text # print(get('https://www.python.org')) print(get('https://www.baidu.com')) #题目八 route_dic={} def make_route(name): def deco(func): route_dic[name]=func return deco @make_route('select') def func1(): print('select') @make_route('insert') def func2(): print('insert') @make_route('update') def func3(): print('update') @make_route('delete') def func4(): print('delete') print(route_dic) #题目九 import time import os def logger(logfile): def deco(func): if not os.path.exists(logfile): with open(logfile,'w'):pass def wrapper(*args,**kwargs): res=func(*args,**kwargs) with open(logfile,'a',encoding='utf-8') as f: f.write('%s %s run ' %(time.strftime('%Y-%m-%d %X'),func.__name__)) return res return wrapper return deco @logger(logfile='aaaaaaaaaaaaaaaaaaaaa.log') def index(): print('index') index()