1.局部变量
在函数内部，可以用Global，显式的声明为全局变量。这种方式永远不要这么用。
Ctrl+？多行注释i
2.高级函数
把函数名当做参数，传给函数
def add(a,b,f):
return f(a)+f(b)
res = add(3,-6,abs)
abs是内置函数
def bar():
print("in the bar")
def test1(func):
首先看第一个例子：
def bar():
print("in the bar")
def test1(func):
print(func)
func()
test1(bar)
<function bar at 0x0000019A43BC2E18>
in the bar
其次看第二个例子：
def bar():
time.sleep(3)
print("in the bar")
def test1(func):
start_time = time.time()
func()
stop_time = time.time()
print("the func run time is: %s" %(stop_time-start_time))
test1(bar)
in the bar
the func run time is: 3.000192880630493
可以看出不修改bar()的源代码下，为其增加功能
最后看第三个例子：
def bar():
print("in the bar")
def test1(func):
print(func)
return func
print(test1(bar))
test1(bar)()
bar = test1(bar)
bar()
<function bar at 0x000002347ACE2E18>
<function bar at 0x000002347ACE2E18>
<function bar at 0x000002347ACE2E18>
in the bar
<function bar at 0x000002347ACE2E18>
in the bar
2.匿名函数：
lambda x:x*3
calc = lambda x:x*3
calc(3)
3.引用计数
python通过引用计数，回收内存
4.嵌套函数
在一个函数体内def另外一个函数
def foo():
print("in the foo")
def bar():
print("int the bar")
def love():
print("int the love")
love()
bar()
foo()
5.装饰器本质是函数，装饰其它函数,为其他函数添加附加功能。语法糖。
1.不能修改被装饰的函数的源代码
2.不能修改被装饰的函数的调用方式
成为透明性
实现：
1函数即“变量”,先定义再使用
2.高级函数
3.嵌套函数
import time
def timer(func):
def deco():
start_time = time.time()
func()
stop_time = time.time()
print("the func run time is: %s" % (stop_time - start_time))
return deco
def test1():
time.sleep(3)
print("in teh tes1")
def test2():
time.sleep(3)
print("in teh tes2")
test1=timer(test1)
test1()
in teh tes1
the func run time is: 3.0001118183135986
最终为：
import time
def timer(func):
def deco():
start_time = time.time()
func()
stop_time = time.time()
print("the func run time is: %s" % (stop_time - start_time))
return deco
@timer #test1=timer(test1)
def test1():
time.sleep(3)
print("in teh tes1")
@timer
def test2():
time.sleep(3)
print("in teh tes2")
test1()
最最终为：import time
def timer(func):
def deco(*args,**kvargs):
start_time = time.time()
func(*args,**kvargs)
stop_time = time.time()
print("the func run time is: %s" % (stop_time - start_time))
return deco
@timer
def test1():
time.sleep(3)
print("in the test1")
@timer
def test2(name,age):
time.sleep(3)
print("in the test",name,age)
test1()
test2("roger",22)
补充：
username,password = "roger","abc123"
def auth(func):
def wrapper(*args,**kvargs):
username = input("Username:")
password = input("Password:")
if username == "roger" and password =="abc123":
print("User has passed authenticated")
func(*args,**kvargs)
else:
print("invalid username or password")
exit()
return wrapper
def index():
print("welcome to index page")
@auth
def home():
print("welcome to home page")
@auth
def bbs():
print("welcome to bbs page")
index()
home()
bbs()
继续：
username,password = "roger","abc123"
def auth(func):
def wrapper(*args,**kvargs):
username = input("Username:")
password = input("Password:")
if username == "roger" and password =="abc123":
print("User has passed authenticated")
resu = func(*args,**kvargs)
print("after authentication")
return resu
else:
print("invalid username or password")
exit()
return wrapper
def index():
print("welcome to index page")
@auth
def home():
print("welcome to home page")
return "from home"
@auth
def bbs():
print("welcome to bbs page")
index()
print(home())
bbs()
再继续：
username,password = "roger","abc123"
def auth(auth_type):
print("auth function args",auth_type)
def out_wrapper(func):
def wrapper(*args, **kvargs):
print("wrapper function args:", *args,*kvargs)
if auth_type == "local":
username = input("Username:")
password = input("Password:")
if username == "roger" and password == "abc123":
print("User has passed authenticated")
resu = func(*args, **kvargs)
print("after authentication")
return resu
else:
print("invalid username or password")
exit()
elif auth_type == "ldap":
print("执行ldap的验证")
return wrapper
return out_wrapper
def index():
print("welcome to index page")
@auth(auth_type="local")
def home():
print("welcome to home page")
return "from home"
@auth(auth_type="ldap")
def bbs():
print("welcome to bbs page")
index()
print(home())
bbs()