Question

I have an excel spreadsheet that has dates in the first column, the rest is the numeric values observed for each attribute. I imported the whole data set using read/readlines function.

How do I separate the imported data into datearray (first column in the imported dataset) and a separate matrix of numeric values ( data that I want to work on)?

For example:

I am importing the following data:

ObservationDate Attribute1 Attribute2 Attribute3

01/01/2012 105 101 100

02/01/2012 101 101 95

03/01/2012 98 95 97

I would like to create the following from this data:

DateArrayList = [01/01/2012, 02/01/2012, 03/01/2012]

             105        101         100   

ValuesMatrix =
101 101 95

             98         95          97

Answer 1

These list comprehensions should do what you’re looking for (assume that the data is in testdata.xls, and that it is tab-delimited):

with open("testdata.xls") as inf:
    next(inf)
    lines = [l[:-1].split("\t") for l in inf]

date_array_list = [l[0] for l in lines]
values_matrix = [map(int, l[1:]) for l in lines]

print date_array_list
print values_matrix

This prints

['01/01/2012', '02/01/2012', '03/01/2012']
[[105, 101, 100], [101, 101, 95], [98, 95, 97]]