How to convert dictionary to matrix in python?

Question

I have a dictionary like this:

{device1 : (news1, news2, ...), device2 : (news 2, news 4, ...)...}

How to convert them into a 2-D 0-1 matrix in python? Looks like this:

         news1 news2 news3 news4
device1    1     1     0      0
device2    0     1     0      1
device3    1     0     0      1

Answer 1

Here is some code that will create a matrix (or 2D array) using the numpy package. Note that we have to use a list of the names in order because dictionaries do not necessarily store the keys/values in the order they are entered.

import numpy as np

dataDict = {'device1':(1,1,0,1), 'device2':(0,1,0,1), 'device3':(1,0,0,1)}
orderedNames = ['device1','device2','device3']

dataMatrix = np.array([dataDict[i] for i in orderedNames])

print dataMatrix

The output is:

[[1 1 0 1]
 [0 1 0 1]
 [1 0 0 1]]

Answer 2

Here is another choice to convert a dictionary to a matrix:

# Load library
from sklearn.feature_extraction import DictVectorizer

# Our dictionary of data
data_dict = [{'Red': 2, 'Blue': 4},
             {'Red': 4, 'Blue': 3},
             {'Red': 1, 'Yellow': 2},
             {'Red': 2, 'Yellow': 2}]
# Create DictVectorizer object
dictvectorizer = DictVectorizer(sparse=False)

# Convert dictionary into feature matrix
features = dictvectorizer.fit_transform(data_dict)
print(features)
#output
'''
[[4. 2. 0.]
 [3. 4. 0.]
 [0. 1. 2.]
 [0. 2. 2.]]
'''
print(dictvectorizer.get_feature_names())
#output
'''
['Blue', 'Red', 'Yellow']
'''