How to customize Pandas columns to align columns of data by subindex?

Question

I have a pandas dataframe df contains data on the financial performance of two stocks:

 >>> df ROIC ROE STK_ID RPT_Date 600141 20110331 0.012 0.022 20110630 0.031 0.063 20110930 0.048 0.103 20111231 0.063 0.122 20120331 0.017 0.033 20120630 0.032 0.077 20120930 0.050 0.120 600809 20110331 0.536 0.218 20110630 0.734 0.278 20110930 0.806 0.293 20111231 1.679 0.313 20120331 0.666 0.165 20120630 1.039 0.257 20120930 1.287 0.359 

And I'm trying to build the ROIC and ROE ratios of the 600141 and 600809 stocks together on the same RPT_Date to compare their performance.

df.plot(kind='bar') below

The chart draws "600141" on the left side, "600809" on the right side. Some inconvenience to compare the "ROIC" and "ROE" of two shares on the same date of the report 'RPT_Date' .

I want the ROIC marker and ROE to be indexed by the same "RPT_Date" in the same group side by side (4 bars per group), and the x axis only marks "RPT_Date", which will clearly indicate the difference in the two stocks.

How to do it?

And if I df.plot(kind='line') , it displays only two lines, but it should be four lines (2 shares * 2 relations):

Is this a mistake or what can I do to fix it? Thanks.

I am using pandas 0.8.1.

Answer 1

If you remove STK_ID, you can create side by side in RPT_Date.

  In [55]: dfu = df.unstack("STK_ID") In [56]: fig, axes = subplots(2,1) In [57]: dfu.plot(ax=axes[0], kind="bar") Out[57]: <matplotlib.axes.AxesSubplot at 0xb53070c> In [58]: dfu.plot(ax=axes[1]) Out[58]: <matplotlib.axes.AxesSubplot at 0xb60e8cc>