# Query the installed extension
 jupyter labextension list
 # Install the corresponding extension from the command line jupyter labextension install @jupyterlab/git
 jupyter labextension install @jupyterlab/github
 jupyter labextension install @jupyterlab/debugger
 jupyter labextension install @krassowski/jupyterlab-lsp
 jupyter labextension install @lckr /jupyterlab_variableinspector
 # Or directly install through the jupyter lab plug-in management # Enter the jupyter interface and click the plug-in icon # Search the corresponding plug-in name in the search bar, such as jupytext, you can install the plug-in directly # Delete the extension jupyter labextension uninstall my-extension

jupyterlab_code_formatter automatic formatting code   
 jupytext ipynb\py\md file conversion
 jupyterlab_spellchecker markdown spelling check
 @krassowski/jupyterlab-lsp automatic completion and jump definition
 @jupyterlab/github         
 @jupyterlab/git

λ jupyter labextension install @jupyterlab/toc
Building jupyterlab assets (build:prod:minimize)
|Exception in thread Thread-10:
Traceback (most recent call last):
  File "e:\python\python36\lib\threading.py", line 916, in _bootstrap_inner
    self.run()
  File "e:\python\python36\lib\threading.py", line 864, in run
    self._target(*self._args, **self._kwargs)
  File "e:\python\python36\lib\subprocess.py", line 1083, in _readerthread
    buffer.append(fh.read())
UnicodeDecodeError: 'gbk' codec can't decode byte 0xa4 in position 281: illegal multibyte sequence

An error occured.
IndexError: list index out of range
See the log file for details:  C:\Users\*****\AppData\Local\Temp\jupyterlab-debug-kx1tois9.log

Mainly this sentence:UnicodeDecodeError: 'gbk' codec can't decode byte 0xa4 in position 281: illegal multibyte sequence

   self.proc = self._create_process(
        cwd=cwd,
        env=env,
        stderr=subprocess.STDOUT,
        stdout=subprocess.PIPE,
        universal_newlines=True
    )

    self.proc = self._create_process(
        cwd=cwd,
        env=env,
        stderr=subprocess.STDOUT,
        stdout=subprocess.PIPE,
        universal_newlines=True,
        encoding="UTF-8"
    )

That is, add a parameter encoding=”UTF-8″, and that’s it.