Convert a dict with array values to pandas dataframe

Question

I have a dictionary with string as keys and arrays as values, like this:

dic = {'x': array([[10],
       [27],
       [12],
       [132]]), 'y': array([[-39],
       [23],
       [42],
       [98]]), 'z': array([[-100],
       [-123],
       [92],
       [88.2]])}

How could i convert it to a pandas dataframe in the following format:

iter x   y   z 
0   10 -39 -100
1   27  23 -123
2   12  42   92
3   132 98  88.2

Tried the following:

df = pd.DataFrame.from_dict(dic)

Getting the following error:

ValueError: Per-column arrays must each be 1-dimensional

not sure where your input is coming from, but if you remove the 'array()' elements you'll get almost what you are looking for. If you also eliminate the sub lists, you'll get what you want. dic = {'x': [10, 27, 12, 132], 'y': [-39, 23, 42, 98], 'z': [-100, -123, 92, 88.2]} — Bill Packard
– Bill Packard, Commented Sep 20, 2022 at 12:58

jezrael · Accepted Answer · 2022-09-20 12:49:44Z

1

Use dict comprehension with numpy.ravel:

df = pd.DataFrame({k: np.ravel(v) for k, v in dic.items()})                  
print (df)
     x   y      z
0   10 -39 -100.0
1   27  23 -123.0
2   12  42   92.0
3  132  98   88.2

Or use map:

df = pd.DataFrame(map(np.ravel, dic.values()), index=dic.keys()).T                
print (df)
       x     y      z
0   10.0 -39.0 -100.0
1   27.0  23.0 -123.0
2   12.0  42.0   92.0
3  132.0  98.0   88.2

answered Sep 20, 2022 at 12:49

jezrael

868k103 gold badges1.4k silver badges1.3k bronze badges

Sign up to request clarification or add additional context in comments.

Comments

mozway · Accepted Answer · 2022-09-20 13:00:00Z

1

You can hstack the numpy arrays and pass them to the DataFrame constructor:

df = pd.DataFrame(np.hstack(list(dic.values())), columns=list(dic))

Or stack, slice, then transpose:

df = pd.DataFrame(np.stack(dic.values())[...,0], index=list(dic)).T

output:

       x     y      z
0   10.0 -39.0 -100.0
1   27.0  23.0 -123.0
2   12.0  42.0   92.0
3  132.0  98.0   88.2

edited Sep 20, 2022 at 13:00

answered Sep 20, 2022 at 12:50

mozway

267k13 gold badges56 silver badges106 bronze badges

Collectives™ on Stack Overflow

Convert a dict with array values to pandas dataframe

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related