How to save a list as numpy array in python?

Question

I need to know if it is possible to save a python list as a numPy array.

Did you try looking on Google or searching stack overflow questions before you posted this?

Bryce Siedschlaw · Accepted Answer · 2011-05-10 15:24:01Z

up vote 4 down vote accepted

If you look here, it might tell you what you need to know.

Basically, you can create an array from a sequence.

from numpy import array
a = array( [2,3,4] )

Or from a sequence of sequences.

from numpy import array
a = array( [[2,3,4], [3,4,5]] )

edited May 10 '11 at 15:24

answered May 10 '11 at 13:57

Bryce Siedschlaw
1,12139

3

wildcard imports :( – Jean-Paul Calderone May 10 '11 at 14:06

Heh, yea... I got lazy. I'll fix it just for you :P – Bryce Siedschlaw May 10 '11 at 15:23

eumiro · Answer 2 · 2011-05-10 14:10:35Z

up vote 2 down vote

You want to save it as a file?

import numpy as np

myList = [1, 2, 3]

np.array(myList).dump(open('array.npy', 'wb'))

... and then read:

myArray = np.load(open('array.npy', 'rb'))

answered May 10 '11 at 14:10

eumiro
46.9k14695

Cédric Julien · Answer 3 · 2011-05-10 13:56:08Z

up vote 0 down vote

you mean something like this ?

from numpy  import array
a = array( your_list )

answered May 10 '11 at 13:56

Cédric Julien
17.6k32343

Felix Kling · Answer 4 · 2011-05-10 13:55:55Z

up vote 1 down vote

a = numpy.array([1,2,3])

answered May 10 '11 at 13:55

Felix Kling
171k17221288

4 Answers