input: from typing import List
  
  
  def match_numeric_strings(string: str) -> bool:
      """ Match all numeric strings using a regular expression in Python.
      >>> match_numeric_strings('123456789')
      True
      >>> match_numeric_strings('abcdef')
      False
      """
      import re
      
      # Regular expression to match all numeric strings
      pattern = '^[0-9]+$'
      
      # Matching a pattern
      result = re.match(pattern, string)
      return bool(result)
output:     import re
      
      # Regular expression to match all numeric strings
      pattern = '^[0-9]+$'
      
      # Matching a pattern
      result = re.match(pattern, string)
      return bool(result)