Introduction to the Python isinstance function

isinstance(object, classinfo)

Determine if the instance is this class or object

object is the variable    
classinfo is type (tuple, dict int, float)  
Determine whether the variable is of this type    

  

class objA:   

pass   

  

A = objA()   

B = 'a','v'   

C = 'a string'   

  

print isinstance(A, objA)   

print isinstance(B, tuple)   

print isinstance(C, basestring)   

Output results:

True   

True   

True   

   
Not only that, but you can use the isinstance function to determine whether an object is of a known type.  
The instructions for isinstance are as follows:  

    isinstance(object, class-or-type-or-tuple) -> bool  

      

    Return whether an object is an instance of a class or of a subclass thereof.  

    With a type as second argument, return whether that is the object's type.  

    The form using a tuple, isinstance(x, (A, B, ...)), is a shortcut for  

    isinstance(x, A) or isinstance(x, B) or ... (etc.).  

The first parameter is an object, and the second is a type name or a list of type names. The return value is Boolean. Returns True if the type of the object is the same as that of parameter 2. If parameter 2 is a tuple, True is returned if the object type is the same as the type name of 1 in the tuple.  

>>>isinstance(lst, list)  

True  

  

>>>isinstance(lst, (int, str, list) )  

True  

In addition, Python can get the type of 1 object, using the type function: > > > lst = [1, 2, 3] > > > type(lst) < type 'list' >