Memory efficient sheet representation
This class wraps around the data read from pyexcel-io. Comparing with
pyexcel.Sheet, the instance of this class does not load all data into memory. Hence it performs better when dealing with big data.
If you would like to do custom rendering for each row of the two dimensional data, you would need to pass a row formatting/rendering function to the parameter “renderer” of pyexcel’s signature functions.
x.__init__(…) initializes x; see help(type(x)) for signature