import os 
def search_file(file_name, search_path, pathsep = os.pathsep): 
  for path in search_path.split(pathsep): 
    candidate = os.path.join(path, file_name) 
    if os.path.isfile(candidate): 
      return os.path.abspath(candidate) 
  return None 
search_path = 'd:\\pm\\pm' 
find_file = search_file('babyos.img', search_path) 
if find_file: 
  print("File 'babyos.img' found at %s" % find_file) 
else: 
  print("File 'babyos.img' not found")