Converting a data dictionary to numpy array in python

Question

im trying to convert a data dictionary with a structure as below:

{'name': array(['Ben','Sean,'Fred'])
 'age': array([22, 16, 35]),
 'marks': array([98, 75, 60]),
 'result': array('HD','D','C')}

I need to then filter out the dictionary to only include name, mark and result in the new numpy array to be able to plot on a graph (i can do this but cant for the life of me filter the list and then convert to numpy)

Sorry original question was meant to be an array with the name, mark and result column, so ignoring the birthday column. So something like array = ['Ben', 'Sean', 'Fred'][98, 75, 60]['HD', 'D', 'C'] — Slacky88, Apr 17 '21 at 05:59
Do you need your numpy array to have nested arrays i.e value of name, marks and result ? Just make it clear how your numpy array should look like. — Hitesh Kumar, Apr 17 '21 at 06:02
You probably want a NumPy "structured array" which you can see how to create here: https://stackoverflow.com/questions/15579649/python-dict-to-numpy-structured-array — John Zwinck, Apr 17 '21 at 06:02

Muhammad Umar · Accepted Answer · 2021-04-17T06:36:31.360

Let's assume your dictionary is something like this.

dict = {
'name': ['Ben','Sean','Fred'],
'age': [22, 16, 35], 
'marks': [98, 75, 60], 
'result': ['HD','D','C']
}

You can iterate over the dictionary to get desired values and append them into a list. Then convert it into a NumPy array. Here I am using all of the keys

name, age, marks, result

but you can filter some keys if you like.

if key not in ['age']:

import numpy as np
data_list = []
for key, val in dict.items():
    data_list.append(val)

numpy_array = np.array(data_list)
transpose = numpy_array.T
transpose_list = transpose.tolist()

The end result will be following:

[['Ben', '22', '98', 'HD'],
['Sean', '16', '75', 'D'],
['Fred', '35', '60', 'C']]

score 0 · Answer 2 · answered Apr 17 '21 at 08:55

You can try pandas

import pandas as pd

d = {
    'name': ['Ben','Sean','Fred'],
    'age': [22, 16, 35],
    'marks': [98, 75, 60],
    'result': ['HD','D','C']
}

df = pd.DataFrame(d)

result = df[['name', 'marks', 'result']].T.values

print(type(result))
print(result)

<class 'numpy.ndarray'>
[['Ben' 'Sean' 'Fred']
 [98 75 60]
 ['HD' 'D' 'C']]

Converting a data dictionary to numpy array in python

2 Answers2