class_docstr: Pandas ExtensionDtype to represent a ragged array datatype
  
  Methods not otherwise documented here are inherited from ExtensionDtype;
  please see the corresponding method on that class for the docstring
class_docstr_tok: ["Pandas","ExtensionDtype","to","represent","a","ragged","array","datatype","Methods","not","otherwise","documented","here","are","inherited","from","ExtensionDtype",";","please","see","the","corresponding","method","on","that","class","for","the","docstring"]
docstr: Parse a datatype string to get the subtype
  
  Parameters
  ----------
  dtype_string: str
      A string like Ragged[subtype]
  
  Returns
  -------
  subtype: str
  
  Raises
  ------
  ValueError
      When the subtype cannot be extracted
code: def _parse_subtype(cls, dtype_string):
      """
      Parse a datatype string to get the subtype
  
      Parameters
      ----------
      dtype_string: str
          A string like Ragged[subtype]
  
      Returns
      -------
      subtype: str
  
      Raises
      ------
      ValueError
          When the subtype cannot be extracted
      """
      # Be case insensitive
      dtype_string = dtype_string.lower()
  
      match = cls._subtype_re.match(dtype_string)
      if match:
          subtype_string = match.groupdict()["subtype"]
      elif dtype_string == "ragged":
          subtype_string = "float64"
      else:
          raise ValueError(
              "Cannot parse {dtype_string}".format(
                  dtype_string=dtype_string
              )
          )
      return subtype_string
  
imports: from __future__ import annotations
  import re
  from functools import total_ordering
  from packaging.version import Version
  import numpy
  import pandas
  from numba import jit
  from pandas.api.extensions import ExtensionDtype, ExtensionArray, register_extension_dtype
  from numbers import Integral
  from pandas.api.types import pandas_dtype, is_extension_array_dtype
label_desc: Use image node_id 7 for calling the RaggedDtype obj's underlying member method code with example usage: obj._parse_subtype(cls, dtype_string) and returns: subtype_string