code: def cdx_filter(cdx_iter, filter_strings):
      
      # Support single strings as well
      if isinstance(filter_strings, str):
          filter_strings = [filter_strings]
  
      filters = [CDXFilter(filter_str) for filter_str in filter_strings]
  
      for cdx in cdx_iter:
          if all(x(cdx) for x in filters):
              yield cdx
docs: filter CDX by regex if each filter is :samp:`{field}:{regex}` form,
      apply filter to :samp:`cdx[{field}]`.