Re-activating this post because I’m having the same issue. I can’t modify the code in the layout tutorial page without Dash going into system error: 1 or package error. I tried putting everything in a jupyter notebook ipynb file, putting the code in a .py file and running it in an ipynb file notebook, using jupyterlabs (found out the lab-dash extension is not yet available in windows) and using the command prompt. Nothing has worked so far. I eager to start building on Dash so hopefully your team can point me in the right direction. I’m attaching some of of the code and error messages I got. Thank you!
Another error:
AttributeError Traceback (most recent call last)
~\Documents\Sebastian\Thinkful\app in <module>
45
46 if _name_ == '_main_':
---> 47 app.run_server(debug=True)
~\Anaconda3\lib\site-packages\dash\dash.py in run_server(self, port, debug, dev_tools_ui, dev_tools_props_check, dev_tools_serve_dev_bundles, dev_tools_hot_reload, dev_tools_hot_reload_interval, dev_tools_hot_reload_watch_interval, dev_tools_hot_reload_max_retry, dev_tools_silence_routes_logging, dev_tools_prune_errors, **flask_run_options)
1924 self.logger.info("Debugger PIN: %s", debugger_pin)
1925
-> 1926 self.server.run(port=port, debug=debug, **flask_run_options)
~\Anaconda3\lib\site-packages\flask\app.py in run(self, host, port, debug, load_dotenv, **options)
988
989 try:
--> 990 run_simple(host, port, self, **options)
991 finally:
992 # reset the first request information if the development server
~\Anaconda3\lib\site-packages\werkzeug\serving.py in run_simple(hostname, port, application, use_reloader, use_debugger, use_evalex, extra_files, reloader_interval, reloader_type, threaded, processes, request_handler, static_files, passthrough_errors, ssl_context)
1005 from ._reloader import run_with_reloader
1006
-> 1007 run_with_reloader(inner, extra_files, reloader_interval, reloader_type)
1008 else:
1009 inner()
~\Anaconda3\lib\site-packages\werkzeug\_reloader.py in run_with_reloader(main_func, extra_files, interval, reloader_type)
330 reloader.run()
331 else:
--> 332 sys.exit(reloader.restart_with_reloader())
333 except KeyboardInterrupt:
334 pass
~\Anaconda3\lib\site-packages\werkzeug\_reloader.py in restart_with_reloader(self)
157 while 1:
158 _log("info", " * Restarting with %s" % self.name)
--> 159 args = _get_args_for_reloading()
160
161 # a weird bug on windows. sometimes unicode strings end up in the
~\Anaconda3\lib\site-packages\werkzeug\_reloader.py in _get_args_for_reloading()
74 _main_ = sys.modules["_main_"]
75
---> 76 if _main_._package_ is None:
77 # Executed a file, like "python app.py".
78 if os.name == "nt":
AttributeError: module '_main_' has no attribute '_package_'