• I have visited the [source website], and in particular
  read the [known issues]
• I have searched through the [issue tracker] for duplicates
• I have mentioned version numbers, operating system and
  environment, where applicable:

  >>> print(tqdm.__version__, sys.version, sys.platform)
  4.31.1 3.6.2 |Continuum Analytics, Inc.| (default, Jul 20 2017, 13:14:59)
  [GCC 4.2.1 Compatible Apple LLVM 6.0 (clang-600.0.57)] darwin
  

refresh=False doesn't work because set_description is overridden and always updates the widget: https://github.com/chengs/tqdm/blob/01ea3170a91e4b30e8e96690b9f70e853bf4ff48/tqdm/_tqdm_notebook.py#L220