python - Creating N-dimensional dynamical array based on user's input?

Question

An ASCII file has 61 columns, from which the columns are read using readlines(). The user has the option to specify how many columns to use to create an n-dimennsional array based on his/her choice of number of columns.

I want to create a dynamic n-dimensional array such as:

from numpy import *
FILE = open('test.txt','rb')

Choice = float(raw_input('How many columns do you want to use: \t'))

A = [[],[],[],...]  # N-dimensional array (rows = 486, columns = N)

such that A has the dimensions based on the user's choice 'Choice'. 'N' can change between 1 and 61. How could I go about doing this?

-Thanks!

Answer 1

>>> rows = 486
>>> columns = 5
>>> A = [[None] * columns for x in xrange(rows)]
>>> len(A)
486
>>> len(A[0])
5

Answer 2

rows = int(raw_input("Number rows: "))
cols = int(raw_input("Number cols: "))

a = np.zeros([rows, cols])

输出：#rows = 3，cols = 2

print a
array([[ 0.,  0.],
       [ 0.,  0.],
       [ 0.,  0.]])

为您的目的设置rows = 1

a = np.zeros([1, cols])