to be deprecated
    Collates data from multiple csv files vertically

    :param fhs: list of paths to csv files
    :param cols: list of column names to concatenate

def fhs2data_combo_appended(fhs, cols=None,labels=None,labels_coln='labels',sep=',',
                           error_bad_lines=True):
    """
    to be deprecated
    Collates data from multiple csv files vertically

    :param fhs: list of paths to csv files
    :param cols: list of column names to concatenate
    """    
    if labels is None:
        labels=[basename(fh) for fh in fhs]
    if len(fhs)>0:
        data_all=pd.DataFrame(columns=cols)
        for fhi,fh in enumerate(fhs):
            label=labels[fhi]
            try:
                data=pd.read_csv(fh,sep=sep,error_bad_lines=error_bad_lines)
            except:
                raise ValueError(f"something wrong with file pd.read_csv({fh},sep={sep})")
            if len(data)!=0:
                data.loc[:,labels_coln]=label
                if not cols is None:
                    data=data.loc[:,cols]
                data_all=data_all.append(data,sort=True)
        return del_Unnamed(data_all)