How to convert pandas columns to double in for loop?

Question

I have a pandas dataframe called df10.

cols10 = list(df10.columns)

I want to change the data type to double where the column name starts with "m_"

for param in cols10:
    if param.startswith("m_"):
        df10[[param]] = df10[[param]].apply(pd.to_double)

However, I'm getting this error:

AttributeError: 'module' object has no attribute 'to_double'

Answer 1

the function to_double doesn't exist in pandas. pandas datatypes are essentially numpy data types

i'm assuming you mean float64 by double

you can either let numpy decide the precision for you

for col in cols10:
    if col.startswith('m_'):
        df[col] = df[col].astype(float)

or specify the precision yourself

for col in cols10:
    if col.startswith('m_'):
        df[col] = df[col].astype(np.float64) # or np.float32 or np.float16

Answer 2

You can do this without loop,

reqd_cols = df10.columns[df10.columns.str.startswith('m_')]
df10[reqd_cols] = df10[reqd_cols].astype('float64')