code: def index_of_first(list_, pred):
      for i, x in enumerate(list_):
          if pred(x):
              return i
  
      return None
  
imports: import argparse
  import commonmark
  import nbformat
  import os
  import re
  import subprocess
  import sys
  import textwrap
  from pathlib import Path
label_desc: Use image node_id 14 for calling a global function with example usage: index_of_first(list_, pred) and returns: None, i