Python dictionary iteration order is unexpectedly sorted. Why? -


this question has answer here:

a dictionary populated consecutive integer keys, this:

d = dict() in range(0, 10):     d[i] = 100-i

later, dictionary items iterated this:

for k, v in d.items():     print k, v

the result shows items iterated in numerical order:

0 100 1 99 2 98 3 97 4 96 5 95 6 94 7 93 8 92 9 91

it turns out, behavior want, not expected. expected dictionary iteration in random order. what's going on here, , can depend on behavior in code released publicly?

dictionaries not in random order. in arbitrary order. in case, got lucky , sorted. tomorrow, might not be. if need randomness, use random. if need sorted order, use sorted(). @benjaminwohlwend mentions in comments, can use collections.ordereddict keep track of insertion order.

in case, guess dictionary doing sort of small-integer-key optimization, acting array (e.g. hash(1) == 1). not guaranteed behavior , might work differently on other python implementations.


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