How to iterate through dict in random order in Python?

Question

How can I iterate through all items of a dictionary in a random order? I mean something random.shuffle, but for a dictionary.

Answer 1

A dict is an unordered set of key-value pairs. When you iterate a dict, it is effectively random. But to explicitly randomize the sequence of key-value pairs, you need to work with a different object that is ordered, like a list. dict.items(), dict.keys(), and dict.values() each return lists, which can be shuffled.

items=d.items() # List of tuples
random.shuffle(items)
for key, value in items:
    print key, value

keys=d.keys() # List of keys
random.shuffle(keys)
for key in keys:
    print key, d[key]

Or, if you don't care about the keys:

values=d.values() # List of values
random.shuffle(values) # Shuffles in-place
for value in values:
    print value

You can also "sort by random":

for key, value in sorted(d.items(), key=lambda x: random.random()):
    print key, value