Why this grouped data frame don't show the expected plot?

Question

I have this pandas data frame, where I want to make a line plot, per each year strata:

    year    month   canasta
0   2011    1   239.816531
1   2011    2   239.092353
2   2011    3   239.332308
3   2011    4   237.591538
4   2011    5   238.384231
... ... ... ...
59  2015    12  295.578605
60  2016    1   296.918861
61  2016    2   296.398701
62  2016    3   296.488780
63  2016    4   300.922927

And I tried this code:

dca.groupby(['year', 'month'])['canasta'].mean().reset_index().plot()

But I get this result:

I must be doing something wrong. Please, could you help me with this plot? The x axis is the months, and there should be a line per each year.

Answer 1

Why: Because after you do reset_index, year and month become normal columns. And some_df.plot() simply plots all the columns of the dataframe into one plot, resulting what you posted.

Fix: Try unstack instead of reset_index:

(dca.groupby(['year', 'month'])
    ['canasta'].mean()
    .unstack('year').plot()
)