unable to convert pandas columns from object to float in python

Question

I'm making using a panda frame containing columns like below:

data = {'chindice': [ '-1', '5.89 e-06', '6.76 e-06', '6.31 e-06', '1',
       '4', np.nan], 
        'target': ['classe1', 'classe2', 'classe3', np.nan,'classe5', 'classe4', 'classe5' ], 
         }
df = pd.DataFrame(data)

I need to use the columns "chindice" as float, but I couldnt because the columns dtype is 'object'. Any help would be appreciated. I am a newbie to pandas. Thanks

Answer 1

You can use to_numeric after stripping the problematic space in your scientific notation entries using str.replace:

In [15]:
df['chindice'] = pd.to_numeric(df['chindice'].str.replace(' ',''), errors='force')
df

Out[15]:
   chindice   target
0 -1.000000  classe1
1  0.000006  classe2
2  0.000007  classe3
3  0.000006      NaN
4  1.000000  classe5
5  4.000000  classe4
6       NaN  classe5

Don't worry about the display, the real value is still there:

In [17]:
df['chindice'].iloc[1]

Out[17]:
5.8900000000000004e-06