Re: Create 2D character matrix

[arsyed]

On Thu, Aug 7, 2008 at 1:36 PM, Simon Parker <si*******@yahoo.co.ukwrote:

Hello.

I want to be able to create a 2D character matrix, ThisMatrix, like :
a A
b B
c C
d D

and to be able to pick out elements, or rows or columns.

I have become used to programming in R where I can easily refer to a row as
:

ThisMatrix [1,]

and a column as

ThisMatrix[,1].

etc..

Can this be done easily in Python ?

You can use numpy:

http://www.scipy.org/NumPy

for example:

In [139]: arr = numpy.char.array(['a', 'A', 'b', 'B', 'c', 'C'])

In [140]: arr = arr.reshape((3,2))

In [141]: arr
Out[141]:
chararray([['a', 'A'],
['b', 'B'],
['c', 'C']],
dtype='|S1')

In [142]: arr[0,:]
Out[142]:
chararray(['a', 'A'],
dtype='|S1')

In [143]: arr[:,0]
Out[143]:
chararray(['a', 'b', 'c'],
dtype='|S1')

More documentation here:

http://mentat.za.net/numpy/refguide/

or take a look at these pages for some quick examples of what's possible:

http://pages.physics.cornell.edu/~my...on/arrays.html
http://www.scipy.org/Numpy_Example_List_With_Doc