Created a function for Converting Datatypes of multiple columns of DataFrame at once

this function takes a data frame,a regular expression(to find that expression in the column names), datatype from users and converts the columns into that particular datatype. The main purpose to create the function was to convert all the columns ending with "_timestamp" will be converted into date time. Please tell me how can i improve it further

class Pandas_made_easy():
    # Made by Jitain Sangwan Alias Pheonix
    def __init__(self) -> None:
        pass
    def dtype_change(dataframe:pd.DataFrame,find:list|str,data_type:str)->None:
        column = list(dataframe.columns)
        l=[]
        if type(find) == str:
            find=[find]
        for i in find:
            pattern = re.compile(i)
            l.extend(list(filter(pattern.match,column)))
        # lambda x : dataframe[x] = dataframe[x].astype(data_type)
        for i in l:
            print(i)    
            dataframe[i] = dataframe[i].astype(data_type)

usage example

Pandas_made_easy.dtype_change(combined,[".*_date$",".*_timestamp$",".*_date$",".*_approved_at$"],"datetime64[ns]")