pandas.to_json output date format in specific form

Question

The original form of date in dataframe is:

Date                                                                   
2018-09-17          12.83  12.92  12.38  12.65         12.65  1937329.0
2018-09-10          12.92  13.12  12.81  12.83         12.83  1150470.0

After converted to json, df.to_json(orient='index',date_format='iso') it looks like this:

"2018-09-17T00:00:00Z":{"

any way to fix this?

Solution

The easiest fix is to first convert your datetime series to an object dtype series of strings:

df['Date'] = df['Date'].dt.strftime('%Y-%m-%d')

I advise you only do this as a final step prior to json conversion, as you lose benefits of vectorised computations and likely will see less efficient memory usage.