Convert one dimensional arrays in a pandas dataframe to numbers

Question

Values of a pandas dataframe contain one dimensional arrays and i would like to convert into floats without the "[]" . Tried this but does not work . How can [0.5142399408894116] be converted to 0.5142399408894116

dfPredictions = pd.DataFrame(data = dff, dtype='float')

Answer 1

Use the index operator [] on the array:

[0.5142399408894116][0]
    = 0.5142399408894116

If you need to apply this to a dataframe row, use the explode method:

df = pd.DataFrame({'col': [[0.5142399408894116], [0.1423994088941165], [0.4239940889411651]]})

df
    col
0   [0.5142399408894116]
1   [0.1423994088941165]
2   [0.4239940889411651]

df.explode('col')

    col
0   0.51424
1   0.142399
2   0.423994