Declarations anywhere in the class(other than in __init__) and declarations in the __init__method are not the same. The following code shows this to be true.Exampleimport sys class foo():     print 'within class'     def __init__(self):         print 'within init'     def do_smthng(self):     ... Read More

In Python 2.x there are two styles of classes depending on the presence or absence of a built-in type as a base-class −‘Old style’ or "Classic" style classes: they have no built-in type as a base class −>>> class OldFoo:      # no base class ...     pass ... Read More

__init__ "__init__" is a reserved method in python classes. It is known as a constructor in OOP concepts. This method called when an object is created from the class and it allows the class to initialize the attributes of a class.How can we use  "__init__ " ?Let's consider that we are ... Read More

The code below shows the if the attribute 'foo' was defined or derived in the classes A and B.Exampleclass A:     foo = 1 class B(A):     pass print A.__dict__ #We see that the attribute foo is there in __dict__ of class A. So foo is defined in ... Read More

You can use the pymongo library in Python to connect to a MongoDB database and use it to insert, update, delete, etc objects in Python. The library supports Python datetime objects out of the box and you dont need to do anything special to insert dates in Mongo using PyMongo. ... Read More

From the Python documentation −Class objects support two kinds of operations: attribute references and instantiation.Attribute references use the standard syntax used for all attribute references in Python: obj.name. Valid attribute names are all the names that were in the class’s namespace when the class object was created. So, if the ... Read More

The following code prints the list of functions of the given class as followsExampleclass foo:     def __init__(self):         self.x = x     def bar(self):         pass     def baz(self):         pass print (type(foo)) import inspect print(inspect.getmembers(foo, predicate=inspect.ismethod))OutputThe output is  [('__init__', ), ('bar', ), ('baz', )]   

In Python 2.x there's two styles of classes depending on the presence or absence of a built-in type as a base-class −"classic" style or old style classes have no built-in type as a base class: >>> class OldSpam:      # no base class ...     pass >>> OldSpam.__bases__ ... Read More

Data hidingIn Python, we use double underscore before the attributes name to make them inaccessible/private or to hide them.The following code shows how the variable __hiddenVar is hidden.Exampleclass MyClass:     __hiddenVar = 0     def add(self, increment):        self.__hiddenVar += increment        print (self.__hiddenVar) ... Read More

The cmp() functionThe cmp(x, y) function compares the values of two arguments x and y −cmp(x, y)The return value is −A negative number if x is less than y.Zero if x is equal to y.A positive number if x is greater than y.The built-in cmp() function will typically return only ... Read More