Python path-Application of function name, closure, iterator

# # #函数名的应用
# def func ():
# Print (666)
# func ()
#
# 1. Function name is the memory address of the function
# Print (func) #结果 <function func at 0x000002ac2188c1e0>

# 2. Function names can be used as variables
# a = 2
# b = A
# c = b
# Print (c)

# def func1 ():
# Print (666)
# F1 = func1 ()
# F2 = F1
# F2 ()

# 3. Function name can be used as parameter of function
# def func1 ():
# Print (666)
# def FUNC2 (x):
# print (x) #<function func1 at 0x0000026c3d983bf8>
# x ()
# func1 ()

# def func ():
# Print (666)
# def func1 ():
# print (123) # Questions
# func ()
# def FUNC2 (x):
# x ()
# FUNC2 (FUNC1)

# 4. Function names can be used as return values of functions
# def Wraaper ():
# def inner ():
# print (' inner ')
# return Inner
# ret = Wraaper () # inner
# RET () # inner ()

# def FUNC2 ():
# print (' in Func ')
#
# def func3 (x):
# print (' in func3 ')
# return X
# F1 = func3 ((Func2 ()))

# F1 ()
# 5. Function name can be used as an element of the container class type
# a = 6
# b = 4
# c = 5
# L1 = [A,b,c]
# print (L1)

# def func1 ():
# print (' in func1 ')
# def FUNC2 ():
# print (' in Func2 ')
# def func3 ():
# print (' in Func2 ')
# def FUNC4 ():
# print (' in Func4 ')
# L1 = [Func1,func2,func3,func4]
# for I in L1:
# I ()

# to the function name above, the first class object

# #返回当前位置的局部变量的字典globals () Locals ()
# # GLOBALS () #返回全局变量的一个字典
# # Locals ()

# def func1 ():
# a= 2
# b = 3
# Print (Globals ()) #返回全局变量的一个字典
# func1 ()

# def func1 (): #返回当前位置局部变量的一个字典
# a = 2 # {' A ': 2, ' B ': 3}
# b = 3
# print (Locals ())
# func1 ()

# Closed Bag
# inner layer function reference to variables (non-global variables) of the outer layer function
# and return, so that a closure is formed

# def Wraaper ():
# name = ' Alex ' #最里层函数调用了上一级的局部变量
# def inner (): #内存种不会立刻消失, again inside the function
# print (name) #调用的话可以调用成功
# Print (inner.__closure__)
# inner ()
# def qwe ():
# print (name)
# qwe ()
# return Inner
#
# Wraaper ()
# print (name)

The effect of "closures"
When the program executes, it encounters the function execution, he will open up a space in memory,
Local namespace, if a closure is formed inside the function
Then he will not disappear with the end of the function.
‘‘‘
#可迭代对象

#对象内部含有_iter_方法就是可迭代对象.
# an Iterative object satisfies an iterative protocol
# Can iterate objects
#str List Dict tuple set Ranger ()

# S1 = ' STRs '
# Print (dir (S1)) #可以查字符串的所有方法

# to determine whether an object is an iterative object
# The first method
# dic = {' name ': ' Alex ', ' age ': ' 18 '}
# print (' __iter__ ' in Dir (DIC))
# Print (dir (DIC))

# S1 = [+]
# Print (dir (S1))
# The second method
# from Collections Import iterable
# from Collections Import Iterator
#
# Print (Isinstance (' Alex ', iterable))
# Print (Isinstance (' Alex ', Iterator)) # True

# Print (Isinstance (' Alex ', str))

# iterators
# object contains __iter__ method and contains __next_ method is iterator
# A file handle is an iterator
# f = open (' T1.txt ', encoding= ' utf-8 ', mode= ' R ')
# print (' __iter__ ' in Dir (f)) #True
# print (' __next__ ' in Dir (f)) #True
# print (' __iter__ ' in Dir (dict)) #False
# print (' __next__ ' in Dir (dict)) #False

# dic = {' name ': ' Alex '}
# print (' __iter__ ' in Dir (DIC)) #True

# The difference between an iterative object and an iterator
# An Iterative object cannot be evaluated, and an iterator can take a value
# An Iterative object can be converted to an iterator

# lis = [1,2,3,4,5,6]
# ite1 = lis.__iter__ () #迭代器
# ite1 = iter (LIS)
# print (ite1) #itel的内存地址
# Print (ite1.__next__ ()) #取迭代器第一个值

# L1 = {' name ': ' Alex '}
# L2 = l1.__iter__ ()
# # L3 = iter (L2)
# Print (l2.__next__ ())

# L1 = [1,2,3,4,5,6,7,8,9,10]
# L2 = l1.__iter__ ()
# Print (l2.__next__ ())

# convert an iterative object to an iterator
# iterator = object can be iterated. __iter__ ()

# How do iterators take values? Next time, go to a value
# Print (ite1.__next__ ())
# Print (ite1.__next__ ())
# Print (ite1.__next__ ())
# Print (ite1.__next__ ())
#调用__next__取值

# 1. An iterative object cannot be evaluated, and an iterator can take a value
# 2. Iterators Save Memory
# 3. Iterators can only take one value at a time
# 4. iterators are one-way, one way to the head

# Use exception handling to stop error
# try

# S1 = ' 1233456 '
# s = s1.__iter__ ()
# while 1:
# try:
# Print (s.__next__ ())
# except Stopiteration:
# break

Python path-Application of function name, closure, iterator