code: def _parse_op(op):
      '''
      >>> _parse_op('>')
      'gt'
      >>> _parse_op('>=')
      'ge'
      >>> _parse_op('=>')
      'ge'
      >>> _parse_op('=> ')
      'ge'
      >>> _parse_op('<')
      'lt'
      >>> _parse_op('<=')
      'le'
      >>> _parse_op('==')
      'eq'
      >>> _parse_op(' <= ')
      'le'
      '''
      op = op.strip()
      if '>' in op:
          if '=' in op:
              return 'ge'
          else:
              return 'gt'
      elif '<' in op:
          if '=' in op:
              return 'le'
          else:
              return 'lt'
      elif '!' in op:
          return 'ne'
      else:
          return 'eqf _parse_op(op):
      '''
      >>> _parse_op('>')
      'gt'
      >>> _parse_op('>=')
      'ge'
      >>> _parse_op('=>')
      'ge'
      >>> _parse_op('=> ')
      'ge'
      >>> _parse_op('<')
      'lt'
      >>> _parse_op('<=')
      'le'
      >>> _parse_op('==')
      'eq'
      >>> _parse_op(' <= ')
      'le'
      '''
      op = op.strip()
      if '>' in op:
          if '=' in op:
              return 'ge'
          else:
              return 'gt'
      elif '<' in op:
          if '=' in op:
              return 'le'
          else:
              return 'lt'
      elif '!' in op:
          return 'ne'
      else:
          return 'eq'
docs: >>> _parse_op('>')
      'gt'
      >>> _parse_op('>=')
      'ge'
      >>> _parse_op('=>')
      'ge'
      >>> _parse_op('=> ')
      'ge'
      >>> _parse_op('<')
      'lt'
      >>> _parse_op('<=')
      'le'
      >>> _parse_op('==')
      'eq'
      >>> _parse_op(' <= ')
      'le'