如何转换熊猫数据框中所有列的数据类型

Question

I have pandas dataframe with 200+ columns. All the columns are of type int. And I need to convert them to float type. I could not find a way to do it. I tried

for column in X_data:
    X_data[column].astype('float64')

But after the for loop, when I print X_data.dtypes , all columns show as int only. I also tried X_data = X_data.apply(pd.to_numeric) but it did not convert to float.

The dataframe is constructed from a csv file load.

Answer 1

If you want to convert specific columns to specific types you can use:

new_type_dict = {
                 'col1': float, 
                 'col2': float
                 } 

df = df.astype(new_type_dict) 

It will now convert the selected columns to new types

I found it from here

Answer 2

The values aren't being saved in place. Try the following:

for column in X_data:
    X_data[column] = X_data[column].astype('float64')