code: def get_scalar(csa_dict, tag_name):
      try:
          items = csa_dict["tags"][tag_name]["items"]
      except KeyError:
          return None
      if len(items) == 0:
          return None
      return items[0]
  
file_path: nibabel/nibabel/nicom/csareader.py
imports: import numpy
  from .structreader import Unpacker
  from .utils import find_private_section
label_desc: Use image node_id 3 for calling a global function with example usage: get_scalar(csa_dict, tag_name) and returns: items, None, None