有参装饰器,叠加多个装饰器,三元表达式,生成式,匿名函数

import time

current_user={'user':None}

def outter(func):
    def wrapper(*args,**kwargs):
        if current_user['user'] is not None:
            res=func(*args,**kwargs)
            return res

        user=input('username>>>: ').strip()
        pwd=input('password>>>: ').strip()
        if user == 'egon' and pwd == '123':
            print('login successfull')
            current_user['user']=user
            res=func(*args,**kwargs)
            return res
        else:
            print('user or password error')
    return wrapper


@outter
def index():
    time.sleep(1)
    print('from index')

@outter
def home(name):
    print('welcome %s' %name)

index()
home('egon')





import time

current_user={'user':None}

def auth(engine='file'):
    def outter(func):
        def wrapper(*args,**kwargs):
            if current_user['user'] is not None:
                res=func(*args,**kwargs)
                return res

            user=input('username>>>: ').strip()
            pwd=input('password>>>: ').strip()

            if engine == 'file':
                # 基于文件的认证
                if user == 'egon' and pwd == '123':
                    print('login successfull')
                    current_user['user']=user
                    res=func(*args,**kwargs)
                    return res
                else:
                    print('user or password error')
            elif engine == 'mysql':
                # 基于mysql的认证
                print('基于mysql的认证')
            elif engine == 'ldap':
                # 基于ldap的认证
                print('基于ldap的认证')
            else:
                print('不知道engine')
        return wrapper
    return outter

@auth('ldap') #@outter #index=outter(index) # index=wrapper
def index():
    time.sleep(1)
    print('from index')

@auth('mysql') #@outter # home=outter(home) #home=wrapper
def home(name):
    print('welcome %s' %name)

index()
home('egon')

 

import time
def outter(func):
    # func=index
    def wrapper(*args,**kwargs):
        start=time.time()
        res=func(*args,**kwargs)
        stop=time.time()
        print(stop-start)
        return res
    return wrapper

from functools import wraps　　　　　　　　#wraps  为与index内的文档返回相同

def outter(func):
    @wraps(func)　　　　　　#所以加上  @wraps
    def wrapper(*args,**kwargs):
        res=func(*args,**kwargs)
        return res
    # wrapper.__name__ = func.__name__
    # wrapper.__doc__ = func.__doc__
    return wrapper

@outter #index=outter(index) #index=wrapper
def index():
    """
    这是index函数....
    :return:
    """
    print('from index')


print(index.__name__) #print(wrapper.__name__)
print(index.__doc__)


叠加多个装饰器
1. 加载顺序(outter函数的调用顺序):自下而上
2. 执行顺序(wrapper函数的执行顺序):自上而下


def outter1(func1): #func1=wrapper2的内存地址
    print('加载了outter1')
    def wrapper1(*args,**kwargs):
        print('执行了wrapper1')
        res1=func1(*args,**kwargs)
        return res1
    return wrapper1

def outter2(func2): #func2=wrapper3的内存地址
    print('加载了outter2')
    def wrapper2(*args,**kwargs):
        print('执行了wrapper2')
        res2=func2(*args,**kwargs)
        return res2
    return wrapper2

def outter3(func3): # func3=最原始的那个index的内存地址
    print('加载了outter3')
    def wrapper3(*args,**kwargs):
        print('执行了wrapper3')
        res3=func3(*args,**kwargs)
        return res3
    return wrapper3



@outter1 # outter1(wrapper2的内存地址)======>index=wrapper1的内存地址
@outter2 # outter2(wrapper3的内存地址)======>wrapper2的内存地址
@outter3 # outter3(最原始的那个index的内存地址)===>wrapper3的内存地址
def index():
    print('from index')

print('======================================================')
index()

'''import time

def timmer(func):
    def aaa(*args,**kwargs):
        start=time.time()
        res=func(*args,**kwargs) #最原始那个index的内存地址()
        stop=time.time()
        print('run time is %s' %(stop -start))
        return res
    return aaa

def auth(func):
    def bbb(*args,**kwargs):
        name=input('name>>>: ').strip()
        pwd=input('pwd>>>: ').strip()
        if name == 'egon' and pwd == '123':
            print('login successfull')
            res=func(*args,**kwargs)
            return res
        else:
            print('user or pwd error')
    return bbb

@timmer
@auth
def index():
    time.sleep(1)
    print('from index')

index()

三元表达式

def max2(x,y):
    if x > y:
        return x
    else:
        return y

res=max2(10,20)

x=10
y=20

res=x if x > y else y
print(res)


res='OK' if False else 'No'
print(res)

生成式

列表生成式
l=[]
for i in range(10):
    if i > 4:
        l.append(i**2)



l=[i**2 for i in range(10) if i > 4]
print(l)


names=['egon','alex_sb','kevin_sb','hxx_sb','cxx_sb']
sbs=[]
for name in names:
    if name.endswith('sb'):
        sbs.append(name)

sbs=[name.upper() for name in names if name.endswith('sb')]



print([name.upper() for name in names])
print([name for name in names if name.endswith('sb')])


字典生成式
res={i:i**2 for i in range(10) if i > 3}
print(res)


print({i for i in 'hello'})






匿名函数

def func():
    print('from func')


func()
func()
func()
匿名函数就是只定义了一个函数的内存地址,主要用于临时使用一次的场景
func=lambda x,y:x+y
print(func)
print(func(1,2))

res=(lambda x,y:x+y)(1,2)
print(res)


print(max([10,11,-3,23]))
salaries={
    'egon':3000,
    'alex':100000000,
    'wupeiqi':10000,
    'yuanhao':2000
}



def func(k):
    return salaries[k]

print(max(salaries,key=lambda k:salaries[k]))
print(min(salaries,key=func))
for循环的结果         比较依据
'egon'                3000
'alex'                100000000
'wupeiqi'             10000
'yuanhao'             2000

l=[4,2,3]
l_new=sorted(l,reverse=True)
print(l_new)


print(sorted(salaries,key=lambda k:salaries[k],reverse=True))

max: 取最大值

　min: 取最小值

　sorted: 排序  从小到大  ,加reverse=True 从大到小

map: 把一个列表按照我们自定义的映射成一个新列表

filter: 从一个列表中过滤出符合我们过滤规则的值

reduce: 把多个值合并成一个结果

eval: 把文件中像字典的字符串,取出打印出时是一个字典