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The example John von Neumann dictionary should read:

person = {
'name' : 'John von Neumann',
'age' : 53,
'occupation' : 'Mathematician',
'birthday' : ('December ', 28, 1903)
}

To have correct birthday and age at death.

In the Advanced Tip on Special Class Methods on the Classes and Object-Oriented Programming page, the description for __repr__() mentions that it is called by print() to produce the string representation of the object. This is not entirely correct, in a subtle way.

print() actually calls __str__() to produce the human-readable string representation of the object. If no custom __str__() implementation is provided by the class, the default implementation merely returns the result of __repr__(). The goal of __repr__() is to return a valid python expression that can be used to recreate the object (if possible).

In the context of introducing beginners to Python, it may be more advisable to teach them about __str__() instead of __repr__().

More info on __repr__() and __str__() is available here.