Inner dictionaries are not displaying in insertion order

[boardtc]

Code Sample

newspapers = {'Jim':{'Mon':15,'Tue':17,'Wed':21,'Thu':16,'Fri':19},\
     'Tony':{'Mon':8,'Tue':15,'Wed':11,'Thu':16,'Fri':13}, \
     'Colin':{'Mon':13,'Tue':17,'Wed':19,'Thu':17,'Fri':20} \
    }
newspapers_df = pd.DataFrame(newspapers)

print(newspapers_df)

Problem description

I am using a recent download of Anaconda with Python 3.7.1 & pandas 0.23.4
The pandas doc says:

When the data is a dict, and an index is not passed, the Series index will be ordered by the dict’s insertion order

I instantiate a pandas DataFrame from a dict with no index passed, and print outputs:

Expected Output

     Jim  Tony  Colin
Mon   15     8     13
Tue   17    15     17
Wed   21    11     19
Thu   16    16     17
Fri   19    13     20

Output of `0.23.4``

      Jim  Tony  Colin
Fri   19    13     20
Mon   15     8     13
Thu   16    16     17
Tue   17    15     17
Wed   21    11     19

[mroeschke]

Could you test this on the latest version of pandas (0.24.2) and master?

I suspect this check is too strict and should be checking for >PY36

pandas/pandas/core/common.py

Line 230 in 31b4019

if PY36 or isinstance(mapping, OrderedDict):

[alexander-ponomaroff]

@mroeschke I tested and this also exists on master. I believe that PY36 check also checks for anything above Python 3.6 from what I remember.

I found what causes this issue and will be making a PR later tonight with a fix for this. One of the functions that gets called has a parameter to sort the Index, this is what is causing the order to be sorted here.

[WillAyd]

Discussed this in associated PR but this isn't something we want to make guarantees about. Closing as won't fix / no change

[boardtc]

Discussed this in associated PR but this isn't something we want to make guarantees about. Closing as won't fix / no change

Why is the community happy to keep a bug in the code?

The logic in the PR is incorrect. From a python-dev message by GvR: "Dict keeps insertion order"