code: def _strictly_valid_num(n):
      n = n.strip()
      if not n:
          return False
      if n[0] == "_":
          return False
      if n[-1] == "_":
          return False
      if "_." in n or "._" in n:
          return False
      if len(n) == 1:
          return True
      if n[0] == "0" and n[1] not in [".", "o", "b", "x"]:
          return False
      if n[0] == "+" or n[0] == "-":
          n = n[1:]
          if len(n) > 1 and n[0] == "0" and n[1] != ".":
              return False
      if "__" in n:
          return False
      return True
  
imports: import datetime
  import io
  from os import linesep
  import re
  import sys
  from toml.tz import TomlTz
label_desc: Use image node_id 4 for calling a global function with example usage: _strictly_valid_num(n) and returns: True, False, False, False, False, True, False, False, False