Intended to normalize to dataframe columns to Hz

get_normalized.py

def get_normalized(df):
    """Normalize frequencies (MHz, GHz) in a DataFrame to Hz."""
    
    SI_PREFIXES = 'yzafpnum kMGTPEZY'
    SI_SCALE_FACTOR = dict([(key, 10**((-8+i)*3)) for i, key in enumerate(SI_PREFIXES)])

    for column in df:
        xHz = [ r for r in re.split(r'[\(*\)]', column) if r not in ''][-1]
        # find eg 'MHz' from the column name 'Frequency (MHz)'

        if xHz[-2:] == 'Hz' and len(xHz) == 3:  # check is both ends 'Hz' and has length to be a prefix
            to = column[:-5] + '(Hz)'  # get column label without (?Hz) and append '(Hz)'
            df = df.rename(columns={column: to})  # rename

            df[to] = SI_SCALE_FACTOR[xHz[0]]*df[to]  # scale to Hz
            # consider rounding to ~ 8 decimal places to cut off multiplication errors

    return df

normalize.py

s = "Frequency of ... (GHz)"
d = 9.87654321123456
SI_PREFIXES = 'yzafpnum kMGTPEZY'
SI_SCALE_FACTOR = dict([(key, 10**((-8+i)*3)) for i, key in enumerate(SI_PREFIXES)])

e = [ r for r in re.split(r'[\(*\)]', s) if r not in ''][-1]
prefix = e[0]
if e[-2:] == 'Hz' and len(e) == 3:
    print(SI_SCALE_FACTOR[prefix]*d)