'Display a single catalog of given key.
If not found, nothing is written out.
Parameters
key : str
Catalog key.
fout : output stream
Default is screen output.'

def print_cat(self, key, fout=None):

    if (fout is None):
        fout = sys.stdout
    str_list = []
    for typ in self.dbtypes:
        if (key in self.catkeys[typ]):
            str_list += [self.dbs[typ].get_catalog(key).dumps(), u'\nFound    in    {0}'.format(typ)]
            break
    if (len(str_list) > 0):
        fout.write((u'\n'.join(str_list) + u'\n'))
