create matrix with column names and row names in Python

Question

I'm very new in Python. I want to create amxn matrix and add names to its columns and rows. I have a list contains row names and a list contains column names. It seems that I need to use "Pandas". But I do not know how to use it. Can any body help me?

Answer 1

You just read in the file with index_col=0 indicating those will be your rownames and pandas automatically gets your colnames from the first row.

m = pd.read_csv("mat.txt,delimiter="\t",index_col=0)

you can convert to a numpy matrix using

m.as_matrix()

to sparse matrix using

import scipy.sparse
scipy.sparse.coo_matrix(m.values)

Hope this helps a bit

Answer 2

Use Pandas DataFrame-

df = pd.DataFrame(index=row_names_list, columns=cols_names_list)

Eg

df = pd.DataFrame(index=['a', 'b', 'c'], columns=['aa', 'bb', 'cc', 'dd'])

Output:

    aa  bb  cc  dd
a   NaN NaN NaN NaN
b   NaN NaN NaN NaN
c   NaN NaN NaN NaN