input: Write a function to develop a regular expression in Python to match all numeric strings. Return True if the string is a valid numeric string, otherwise return False. If the input string is empty, return False.
  assert match_numeric_string('123456789')==True
  assert match_numeric_string('abc123')==False
  assert match_numeric_string('')==False
  assert match_numeric_string('9876543210')==True
  assert match_numeric_string('0')==True
output: def match_numeric_string(s):
      import re
      pattern = r'^\d+$'
      return bool(re.match(pattern, s))