Support for Reading Excel Files with Hierarchical Columns Names

[cancan101]

related #4438 #4679

For example see the "INCOME_STATEMENT" sheet on http://shareholder.api.edgar-online.com/efx_dll/edgarpro.dll?FetchFilingXLS1?sessionid=F7D_689jk-BEFvN&ID=9277772

There are four columns in the desired DataFrame:

1           2               3           4
Thirteen weeks ended        Twenty-six weeks ended  
March 30,   March 24,       March 30,   March 24,

Currently the ExcelFile parser only takes an int for the header parameter, whereas the html parser takes "The row (or rows for a MultiIndex) to use to make the columns headers."

[jreback]

try this: http://pandas.pydata.org/pandas-docs/dev/io.html#reading-columns-with-a-multiindex

[cancan101]

@jreback Isn't that just for reading from csv?

[jreback]

ahh...it needs a slight modification I think to work (it uses TextParser under the hood which is passed the header), but something going on at a higher level....so not implemented for now

[jreback]

closing as dupe of #4679