pyexcel.Sheet.columns

Sheet.columns()

Returns a left to right column iterator

import pyexcel as pe
data = [
    [1, 2, 3, 4],
    [5, 6, 7, 8],
    [9, 10, 11, 12]
]
m = pe.Matrix(data)
print(pe.utils.to_array(m.columns()))
[[1, 5, 9], [2, 6, 10], [3, 7, 11], [4, 8, 12]]

More details see ColumnIterator