Question

pprint sorts dicts keys alphabetically, print sorts them in default order.

from pprint import pprint
d = {'foo': 1, 'bar': 2, 'baz': 3}

pprint(d)
# {'bar': 2, 'baz': 3, 'foo': 1}

print d
# {'baz': 3, 'foo': 1, 'bar': 2}

The documentation of pprint mentions this, but does not say why. Why the discrepancy?

Answer 1

pprint stands for “pretty print”, also implying “pleasing to the human eye, and easily read by humans”. Sorting the dict keys just follows that aim, pprint isn’t supposed to be primarily fast (sorting the keys adds a penalty), but, errr, pretty. 🙂

print on the other hand “just prints”, as fast as possible. Actually the discrepancy here is between dict‘s __str__ and pprint‘s specially crafted string conversion.