1、tensorflow的程式中,在main函式下,都是使用tf.app.run()來啟動

if __name__ == "__main__":
  tf.app.run()

"""Generic entry point script."""
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function

import sys

from tensorflow.python.platform import flags


def run(main=None, argv=None):
  """Runs the program with an optional 'main' function and 'argv' list."""
  f = flags.FLAGS

  # Extract the args from the optional `argv` list.
  args = argv[1:] if argv else None

  # Parse the known flags from that list, or from the command
  # line otherwise.
  # pylint: disable=protected-access
  flags_passthrough = f._parse_flags(args=args)
  # pylint: enable=protected-access

  main = main or sys.modules['__main__'].main

  # Call the main function, passing through any arguments
  # to the final program.
  sys.exit(main(sys.argv[:1] + flags_passthrough))