How to print instances of a class using print()?

Question

I am learning the ropes in Python. When I try to print an object of class Foobar using the print() function, I ge

Answer 1

Just to add my two cents to @dbr's answer, following is an example of how to implement this sentence from the official documentation he's cited:

"[...] to return a string that would yield an object with the same value when passed to eval(), [...]"

Given this class definition:

class Test(object):
    def __init__(self, a, b):
        self._a = a
        self._b = b

    def __str__(self):
        return "An instance of class Test with state: a=%s b=%s" % (self._a, self._b)

    def __repr__(self):
        return 'Test("%s","%s")' % (self._a, self._b)

Now, is easy to serialize instance of Test class:

x = Test('hello', 'world')
print 'Human readable: ', str(x)
print 'Object representation: ', repr(x)
print

y = eval(repr(x))
print 'Human readable: ', str(y)
print 'Object representation: ', repr(y)
print

So, running last piece of code, we'll get:

Human readable:  An instance of class Test with state: a=hello b=world
Object representation:  Test("hello","world")

Human readable:  An instance of class Test with state: a=hello b=world
Object representation:  Test("hello","world")

But, as I said in my last comment: more info is just here!