Make a class from the command line and show quirks of inheritance after instantiation

fred-has-classy-pants.py

>>> from __future__ import print_function
>>> class People: pass
>>>
>>> Fred = People()
>>> Fred.has_pants = True

# Now I'd like to create a method that says "I have pants" if Fred has pants.  I make the function:

>>> f = lambda self: print("I have pants") if self.has_pants else None

# Now try to assign it to the class:

>>> setattr(People,"talk_about_pants",f)
>>> Fred.talk_about_pants()
I have pants

>>> f = lambda self,y: print("I have %s" % y)
>>> setattr(People,"say_this",f)
>>> Fred.say_this("rock and roll")
I have rock and roll