[Python daily use] isinstance() function in python

grammar

isinstance(object, classinfo)

Function definition

def isinstance(x, A_tuple): # real signature unknown; restored from __doc__
    """
    Return whether an object is an instance of a class or of a subclass thereof.
    
    A tuple, as in ``isinstance(x, (A, B, ...))``, may be given as the target to
    check against. This is equivalent to ``isinstance(x, A) or isinstance(x, B)
    or ...`` etc.
    """
    pass

To put it simply, the isinstance() function determines whether an object is a known type, similar to type().
But it is different from type:

• type() does not consider the subclass to be a parent type, and does not consider the inheritance relationship.
• isinstance() will consider the subclass to be a parent class type, and consider the inheritance relationship.
  The classinfo here can be for ordinary types
• int，
• float，
• bool，
• complex，
• str (string),
• list，
• dict (dictionary),
• set，
• tuple

Example

isinstance(2,int)