python3 (twenty-five) getClassInfo

"" "   " "" 
__Author__ = ' shaozhiqi ' 

#   How do we know that the object what type, use type () 
Print (type (123))   # <class 'int'> 
Print (type ( ' ABC ' ))   # <class 'STR'> 
Print (type (None))   # <class 'NoneType'> 
Print (type (ABS))   # <class 'builtin_function_or_method'>
print(type(123) == type(456))  # True
print(type(123) == int)  # True
print(type('abc') == STR)   # True 
Print (type ( ' ABC ' ) == type (123))   # False 
# determines whether an object is a function of 
Import types 


DEF Fn ():
     Pass 


Print (type (Fn) == types.FunctionType )   # True 
Print (of the type (ABS) == types.BuiltinFunctionType)   # True 

# on isinstance () is to determine whether an object is the type itself, or in the type of parent inheritance chain 
# as described in section twenty-four 
# Print (the isinstance (Dog, Animal)) True # 
# can type () can also be substantially determined by the type of the isinstance () 
Print (the isinstance ( ' a ', STR))   # True 
Print (the isinstance (123, int))   # True 
Print (the isinstance (B ' A ' , bytes))   # True 
# the isinstance may determine whether a variable is a certain type of 
Print (the isinstance ( [. 1, 2,. 3 ], (List, tuple))) 

# the dir () ------------------------------- ------------------------- 
# all the properties and methods of obtaining an object, you can use dir () function, which returns a string containing the list 
Print (the dir ( ' the ABC ' ))
 # ['__add__', '__class__', '__contains__', '__delattr__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__getitem__', '__getnewargs__', '__gt__', '__hash__', '__init__', '__init_subclass__', '__iter__', '__le__', '__len__', '__lt__', '__mod__', '__mul__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__rmod__', '__rmul__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', 'capitalize', 'casefold', 'center', 'count', 'encode', 'endswith', 'expandtabs', 'find', 'format', 'format_map', 'index', 'isalnum', 'isalpha', 'isascii', 'isdecimal', 'isdigit', 'isidentifier', 'islower', 'isnumeric', 'isprintable', 'isspace', 'istitle', 'isupper', 'join', 'ljust', 'lower', 'lstrip', 'maketrans', 'partition', 'replace', 'rfind', 'rindex', 'rjust', 'rpartition', 'rsplit', 'rstrip', 'split', 'splitlines', 'startswith', 'strip', 'swapcase', 'title', 'translate', 'upper', 'zfill']
# Similar __xxx__ properties and methods in Python are all special purpose, such as the method returns __len__ length. 
# In Python, if you call len () function tries to get the length of an object, in fact, inside the len () function, which automatically went to call the object's __len __ () method 
Print (len ( ' ABC ' ))   # 3 
Print ( ' ABC ' . __len__ ())   # 3 


# can also be defined in our own writing class __len__ 
class myDog (Object): 

    DEF  __init__ (Self): 
        self.nameDog = ' Dog ' 

    DEF  __len__ ( Self):
         return 100 DEF RUN (Self):
        

    Print ( ' running ....... ' ) 


Dog = myDog ()
 Print (len (Dog))   # 100 deleted __len__ method given 
Print ( ' the ABC ' .lower ())   # ABC 

Print (the hasattr (Dog , ' nameDog ' ))   # True there you have nameDog property 
Print (hasattr (Dog, ' color ' ))   # False no color attribute 

setattr (Dog, ' color ' , ' black and white ' )   #Setting a property 'Color' 
Print (the hasattr (Dog, ' Color ' ))   # True 
Print (getattr (Dog, ' Color ' ))   # monochrome attribute value acquired Among 
Print (dog.color)   # Among 
Print (getattr (Dog , ' Age ' , ' 404 ' ))   # 404 acquires nonexistent property will be reported error, set the default value processing 404 

# acquired object methods 
Print (the hasattr (Dog, ' RUN ' ))   # True 
Fn = getattr (Dog , ' RUN' ) 
Fn ()   # running ....... 


# ---------- attribute instance ---------------------- -------------------------- 
class Student (Object): 
    name = ' Student ' 

    DEF  the __init__ (Self, name): 
        the self.name = name 


S = Student ( ' Bob ' ) 
s.score = 90
 Print (s.name, ' , ' , s.score)   # Bob, 90 
Print (Student.name)   # Student 
# deleted property 
dels.name
 Print (s.name, ' , ' , s.score)   # Student, 90 
Student.name = ' student1 ' 
Print (s.name, ' , ' , s.score)   # student1, 90 
# If instance attribute and class attributes with the same name, the class instance attributes will overwrite property, so the actual development avoided. Unless there is real business need to do so