Will a Python dict literal be evaluated in the order it is written?

Question

Let\'s say that I\'ve got a situation like this in Python:

_avg = {\'total\':0.0, \'count\':0}    # HACK: side-effects stored here

def procedure(n):
  _avg[         


        

Answer 1

According to the Python docs regarding evaluation order, this should have well-defined behavior:

In the following lines, expressions will be evaluated in the arithmetic order of their suffixes:

…
{expr1: expr2, expr3: expr4}
…

So, regardless of what order the items in a dict end up being iterated, the values (and keys!) of a literal dictionary expression will always be evaluated in the same order as they appear in my Python source code.