How would I change/remove 'non-printable' characters e.g  from df.columns values incorporating the regex statements already in place

Have tried the above with no success. Note ..This is specific to the text Column Headings and not the Column Values

df.columns = [x.lower().replace(" ","").replace("?","").replace("_","").replace( "Â" , "") for x in df.columns]

Would have replaced the non-printable character but has failed.

Can anyone help ?