【python之旅】python的基础三

 1 #!/usr/bin/env python
 2 # -*- coding: utf-8 -*-
 3 # Author :GU
 4 import time
 5 def timmer(func):   ##后加的一个记录运行时间的装饰器
 6     def warpper(*args,**kwargs):
 7         start_time= time.time()
 8         func()
 9         stop_time=time.time()
10         print("The func run timr is %s"%(stop_time-start_time))
11     return warpper
12 @timmer   ##把装饰器调用到函数test1函数里面去
13 def test1():
14     time.sleep(3)
15     print("In the test1")
16 test1()
17 执行结果：
18 In the test1
19 The func run timr is 3.000171661376953

 2 def foo():
 3     print (‘in the foo‘)
 4     bar()
 5 foo()
 6 报错：
 7 in the foo
 8 Traceback (most recent call last):
 9   File "<pyshell#13>", line 1, in <module>
10     foo()
11   File "<pyshell#12>", line 3, in foo
12     bar()
13 NameError: global name ‘bar‘ is not defined
14 =====================================
15 def foo():
16     print (‘foo‘)
17     bar()
18 foo()
19 def bar():
20     print (‘bar‘)
21 报错：NameError: global name ‘bar‘ is not define

 1 def bar():
 2     print (‘in the bar‘)
 3 def foo():
 4     print (‘in the foo‘)
 5     bar()
 6      
 7 foo()
 8  ===================================
 9 def foo():
10     print (‘in the foo‘)
11     bar()
12 def bar():
13     print (‘in the bar‘)
14 foo()
15 执行结果：
16 in the foo
17 in the bar
18 =======================
19 in the foo
20 in 

 1 #不修改被装饰函数源代码的情况下为其添加功能
 2 import time
 3 def bar():
 4     time.sleep(3)
 5     print(‘in the bar‘)
 6 
 7 def test1(func):
 8     start_time=time.time()
 9     func()    #run bar
10     stop_time=time.time()
11     print("the func run time is %s" %(stop_time-start_time))
12 
13 test1(bar)
14 执行结果：
15 in the bar
16 the func run time is 3.000171661376953

 1 #不修改函数的调用方式
 2 import time
 3 def bar():
 4     time.sleep(3)
 5     print(‘in the bar‘)
 6 def test2(func):
 7     print(func)
 8     return func
 9 
10 # print(test2(bar))
11 bar=test2(bar)
12 bar()  #run bar
13 执行结果：
14 <function bar at 0x00000000007DE048>
15 in the bar

1 def foo():
2     print(‘in the foo‘)
3     def bar():
4         print(‘in the bar‘)
5     bar()
6 foo()
7 执行结果：
8 in the foo
9 in the bar

 1 x=0
 2 def grandpa():
 3     x=1
 4     def dad():
 5         x=2
 6         def son():
 7             x=3
 8             print(x)
 9         son()
10     dad()
11 grandpa()
12 执行结果：
13 3

 1 import time
 2 def timer(func): #timer(test1)  func=test1
 3     def deco():
 4         start_time=time.time()
 5         func()   #run test1()
 6         stop_time = time.time()
 7         print("the func run time  is %s" %(stop_time-start_time))
 8     return deco
 9 @timer  #test1=timer(test1)
10 def test1():
11     time.sleep(1)
12     print(‘in the test1‘)
13 #执行结果：
14 in the test1
15 the func run time  is 1.0000572204589844

 1 import time
 2 def timer(func): #timer(test1)  func=test1
 3     def deco(*args,**kwargs):
 4         start_time=time.time()
 5         func(*args,**kwargs)   #run test1()
 6         stop_time = time.time()
 7         print("the func run time  is %s" %(stop_time-start_time))
 8     return deco
 9 @timer  #test1=timer(test1)
10 def test1():
11     time.sleep(1)
12     print(‘in the test1‘)
13 @timer # test2 = timer(test2)  = deco  test2(name) =deco(name)
14 def test2(name,age):
15     time.sleep(1)
16     print("test2:",name,age)
17 test1()
18 test2("alex",22)
19 执行结果：
20 in the test1
21 the func run time  is 1.0000572204589844
22 test2: alex 22
23 the func run time  is 1.000057220458984

user,passwd = ‘alex‘,‘abc123‘
def auth(auth_type):
    print("auth func:",auth_type)
    def outer_wrapper(func):
        def wrapper(*args, **kwargs):
            print("wrapper func args:", *args, **kwargs)
            if auth_type == "local":
                username = input("Username:").strip()
                password = input("Password:").strip()
                if user == username and passwd == password:
                    print("\033[32;1mUser has passed authentication\033[0m")
                    res = func(*args, **kwargs)  # from home
                    print("---after authenticaion ")
                    return res
                else:
                    exit("\033[31;1mInvalid username or password\033[0m")
            elif auth_type == "ldap":
                print("搞毛线ldap,不会。。。。")
        return wrapper
    return outer_wrapper
def index():
    print("welcome to index page")
@auth(auth_type="local") # home = wrapper()
def home():
    print("welcome to home  page")
    return "from home"

@auth(auth_type="ldap")
def bbs():
    print("welcome to bbs  page")

index()
print(home()) #wrapper()
bbs()
###执行结果：
auth func: local
auth func: ldap
welcome to index page
wrapper func args:
Username:alex
Password:abc123
User has passed authentication
welcome to home  page
---after authenticaion 
from home
wrapper func args:
搞毛线ldap,不会。。。。

1 >>> l = [x * x for x in range(10)]
2 >>> l
3 [0, 1, 4, 9, 16, 25, 36, 49, 64, 81]
4 >>> g = (x * x for x in range(10))
5 >>> g
6 <generator object <genexpr> at 0x00000000006F3048>

 1 >>> next(g)
 2 0
 3 >>> next(g)
 4 1
 5 >>> next(g)
 6 4
 7 >>> next(g)
 8 9
 9 >>> next(g)
10 16
11 >>> next(g)
12 25
13 >>> next(g)
14 36
15 >>> next(g)
16 49

 1 >>> for n in g:
 2 ...     print(n)
 3 ...
 4 0
 5 1
 6 4
 7 9
 8 16
 9 25
10 36
11 49
12 64
13 81

 1 def fib(max):
 2     n, a, b = 0, 0, 1
 3     while n < max:
 4         print(b)
 5         a, b = b, a + b   ##相当于
 6         n = n + 1
 7     return ‘done‘
 8 fib(5)  ##打印前五个数列
 9 #####执行结果
10 1
11 1
12 2
13 3
14 5
15 ===============
16 a, b = b, a + b   ##相当于
17 t = (b, a + b) # t是一个tuple
18 a = t[0]
19 b = t[1]

 1 def fib(max):
 2     n, a, b = 0, 0, 1
 3     while n < max:
 4         #print(b)
 5         yield b    ###返回当前状态的值
 6         a, b = b, a + b
 7         n = n + 1
 8     return ‘done‘
 9 gen = fib(5)
10 print(gen.__next__())
11 print(gen.__next__())
12 print(gen.__next__())
13 print(gen.__next__())
14 执行结果：
15 1
16 1
17 2
18 3

 1 def fib(max):
 2     n, a, b = 0, 0, 1
 3     while n < max:
 4         #print(b)
 5         yield b
 6         a, b = b, a + b
 7         n = n + 1
 8     return ‘done‘
 9 for i in fib(5):
10     print(i)
11 #执行结果：
12 1
13 1
14 2
15 3
16 5

 1 def fib(max):
 2     n, a, b = 0, 0, 1
 3     while n < max:
 4         #print(b)
 5         yield b
 6         a, b = b, a + b
 7         n = n + 1
 8     return ‘done‘
 9 g = fib(6)
10 while True:
11     try:
12         x = next(g)
13         print(‘g:‘, x)
14     except StopIteration as e:
15         print(‘Generator return value:‘, e.value)
16         break
17 ###执行结果;
18 g: 1
19 g: 1
20 g: 2
21 g: 3
22 g: 5
23 g: 8
24 Generator return value: done

 1 >>> from collections import Iterable
 2 >>> isinstance([],Iterable)
 3 True
 4 >>> isinstance({},Iterable)
 5 True
 6 >>> isinstance("abc",Iterable)
 7 True
 8 >>> isinstance((x for x in range(10)), Iterable)
 9 True
10 >>> isinstance(100, Iterable)
11 False

1 >>> from collections import Iterator
2 >>> isinstance((x for x in range(10)), Iterator)
3 True
4 >>> isinstance([], Iterator)
5 False
6 >>> isinstance({}, Iterator)
7 False
8 >>> isinstance(‘abc‘, Iterator)
9 False

1 >>> isinstance(iter([]), Iterator)
2 True
3 >>> isinstance(iter(‘abc‘), Iterator)
4 True

1 for x in [1, 2, 3, 4, 5]:
2     pass

 1 # 首先获得Iterator对象:
 2 it = iter([1, 2, 3, 4, 5])
 3 # 循环:
 4 while True:
 5     try:
 6         # 获得下一个值:
 7         x = next(it)
 8     except StopIteration:
 9         # 遇到StopIteration就退出循环
10         break

 1 #!/usr/bin/env python
 2 # -*- coding: utf-8 -*-
 3 # Author :GU
 4 import json
 5 info = {
 6     ‘name‘:‘alex‘,
 7     ‘age‘:22,
 8 }
 9 f = open("test.text","w")
10 f.write( json.dumps( info) )   ###用dunmps序列化
11 f.close()
12 ##执行结果：
13 {"name": "alex", "age": 22}

1 #!/usr/bin/env python
2 # -*- coding: utf-8 -*-
3 # Author :GU
4 import json
5 f = open("test.text","r")
6 data = json.loads(f.read())   ###loads反序列化
7 print(data["age"])
8 ###执行结果：
9 22

 1 #!/usr/bin/env python
 2 # -*- coding: utf-8 -*-
 3 # Author :GU
 4 import pickle
 5 def sayhi(name):
 6     print("hello,",name)
 7 info = {
 8     ‘name‘:‘alex‘,
 9     ‘age‘:22,
10     "func":sayhi,
11 }
12 f = open("test.text","wb")
13 f.write( pickle.dumps( info) )
14 f.close()
15 执行结果：
16 ?}q (X   funcq
c__main__
17 sayhi
18 qX   nameqX   alexqX   ageqKu.

 1 #!/usr/bin/env python
 2 # -*- coding: utf-8 -*-
 3 # Author :GU
 4 import pickle
 5 def sayhi(name):
 6     print("hello,",name)
 7 f = open("test.text","rb")
 8 data = pickle.loads(f.read())
 9 print(data["func"]("alex"))
10 执行结果：
11 hello, alex
12 None