code: def count_lines(f):
      if path.isfile(f):
          num_lines = sum(1 for line in open(f))
          return num_lines
      else:
          return 0
  
file_path: deepwalk/deepwalk/walks.py
imports: import logging
  from io import open
  from os import path
  from time import time
  from multiprocessing import cpu_count
  import random
  from concurrent.futures import ProcessPoolExecutor
  from collections import Counter
  from six.moves import zip
  from .None import graph
label_desc: Use image node_id 3 for calling a global function with example usage: count_lines(f) and returns: num_lines, int