How can I sort DataFrame by date in Python?

Question

I try to sort dataframe shown below by date using df.sort_values(by='date') however it doesn't work. Any ideas how can I do this to be sure that it is sorted properly?

     symbol        date     open    close     high      low
0      GOOG  2007-01-03   232.77   233.56   238.09   230.32
1      GOOG  2007-01-05   241.01   243.35   243.51   238.82
2      GOOG  2007-01-04   234.27   241.39   241.73   233.94

...
2692   GOOG  2017-11-30  1022.37  1021.41  1028.49  1015.00
2693   GOOG  2017-11-29  1042.68  1021.66  1044.08  1015.65
2694   GOOG  2017-12-01  1015.80  1010.17  1022.49  1002.02

Answer 1

If you have a dataframe like this below:

df = pd.DataFrame({'col1' : ['A', 'A', 'B', np.nan, 'D', 'C'],
'col2' : [2, 1, 9, 8, 7, 4],
'col3': [0, 1, 9, 4, 2, 3], })

This is how you sort it:

df = df.sort_values(by=['col1'])

Similar problem with solution on stackoverflow: how to sort pandas dataframe from one column Panda reference : http://pandas.pydata.org/pandas-docs/version/0.19.2/generated/pandas.DataFrame.sort.html

Answer 2

df.sort_values() returns sorted DF, but it doesn't sort in place.

So either use:

df = df.sort_values(by='date') 

or

df.sort_values(by='date', inplace=True)

Answer 3

Try

df['Date']=pd.to_datetime(df.Date)
df.sort_values(['Date'])