Json import sorting

Noticed that if export a df to json file and then reload the data, ordering is not kept.

import pandas as pd

df.to_json('test.json')
newdf = pd.read_json('test.json')

print df.index

gives:

1
10
100
....

instead of

1
2
3
....

it suffices to call newdf = pd.read_json('test.json').sort() to have the what I’d expect.

Is this intended behaviour or bug?

[Komnomnomnom]

BTW @ghego if you want to ensure that order is preserved during roudtrip JSONifying try using orient=split

n [27]: pd.read_json(df.to_json(orient='split'), orient='split')
[0]
Out[27]: 
     foo
1      1
2      2
3      3
4     10
10    11
11    20
100  100
101  101

[Komnomnomnom]

@jreback #5287 eventually got there. Thanks for the reminders.