Convert Select Columns in Pandas Dataframe to Numpy Array

Question

I would like to convert everything but the first column of a pandas dataframe into a numpy array. For some reason using the columns= parameter of DataFrame.to_matrix() is not working.

df:

  viz  a1_count  a1_mean     a1_std 0   n         3        2   0.816497 1   n         0      NaN        NaN  2   n         2       51  50.000000 

I tried X=df.as_matrix(columns=[df[1:]]) but this yields an array of all NaNs

Answer 1

the easy way is the "values" property df.iloc[:,1:].values

a=df.iloc[:,1:] b=df.iloc[:,1:].values  print(type(df)) print(type(a)) print(type(b)) 

so, you can get type

<class 'pandas.core.frame.DataFrame'> <class 'pandas.core.frame.DataFrame'> <class 'numpy.ndarray'>