How to import csv file as numpy.array in python? [duplicate]

Question

Say I have a CSV file.csv in this format:

dfaefew,432,1
vzcxvvz,300,1
ewrwefd,432,0

How to import the second column as a NumPy array and the third column as another one like this:

second = np.array([432, 300, 432])
third = np.array([1, 1, 0])

Answer 1

numpy.genfromtxt() is the best thing to use here

import numpy as np csv = np.genfromtxt ('file.csv', delimiter=",") second = csv[:,1] third = csv[:,2]  >>> second Out[1]: array([ 432.,  300.,  432.])  >>> third Out[2]: array([ 1.,  1.,  0.]) 

Answer 2

You can use numpy.loadtxt:

In [15]: !cat data.csv
dfaefew,432,1
vzcxvvz,300,1
ewrwefd,432,0

In [16]: second, third = loadtxt('data.csv', delimiter=',', usecols=(1,2), unpack=True, dtype=int)

In [17]: second
Out[17]: array([432, 300, 432])

In [18]: third
Out[18]: array([1, 1, 0])

Or numpy.genfromtxt

In [19]: second, third = genfromtxt('data.csv', delimiter=',', usecols=(1,2), unpack=True, dtype=None)

The only change in the arguments is that I used dtype=None, which tells genfromtxt to infer the data type from the values that it finds in the file.