code: def valid_name(name):
      r"""Determine whether or not the given string is a valid
      alphanumeric string.
  
      Parameters
      ----------
      name : str
          An alphanumeric identifier.
  
      Returns
      -------
      result : bool
          ``True`` if the name is valid, else ``False``.
  
      Examples
      --------
  
      >>> valid_name('alpha')   # True
      >>> valid_name('!alpha')  # False
  
      """
      identifier = re.compile(r"^[^\d\W]\w*\Z", re.UNICODE)
      result = re.match(identifier, name)
      return result is not None
  
file_path: AlphaPy/alphapy/utilities.py
imports: from alphapy.globals import PSEP, SSEP, USEP
  import argparse
  from datetime import datetime, timedelta
  import glob
  import inspect
  from itertools import groupby
  import logging
  import numpy
  import os
  from os import listdir
  from os.path import isfile, join
  import re
label_desc: Use image node_id 7 for calling a global function with example usage: valid_name(name) and returns: unknown