从终端运行时，ipython 显示无效语法

我使用 python 3.7，但也安装了 3.6 和 2.7，我使用的是 Ubuntu 16.04 LTS。

我将 python 的顺序更改为 python 2.7 仍然无法正常工作，我在 VMware 上使用它。我想我对 python3 进行了更改，我安装了很多包。

我正在尝试运行 jupyter notebook，但我无法弄清楚可能导致问题的原因。

当我尝试从终端运行 ipython 时，它显示：

stealth@ubuntu:~/Desktop$ ipython
Traceback (most recent call last):
  File "/home/stealth/.local/bin/ipython", line 7, in <module>
    from IPython import start_ipython
  File "/home/stealth/.local/lib/python3.7/site-packages/IPython/__init__.py", line 55, in <module>
    from .core.application import Application
  File "/home/stealth/.local/lib/python3.7/site-packages/IPython/core/application.py", line 25, in <module>
    from IPython.core import release, crashhandler
  File "/home/stealth/.local/lib/python3.7/site-packages/IPython/core/crashhandler.py", line 27, in <module>
    from IPython.core import ultratb
  File "/home/stealth/.local/lib/python3.7/site-packages/IPython/core/ultratb.py", line 116, in <module>
    from IPython.utils import path as util_path
  File "/home/stealth/.local/lib/python3.7/site-packages/IPython/utils/path.py", line 17, in <module>
    from IPython.utils.process import system
  File "/home/stealth/.local/lib/python3.7/site-packages/IPython/utils/process.py", line 19, in <module>
    from ._process_posix import system, getoutput, arg_split, check_pid
  File "/home/stealth/.local/lib/python3.7/site-packages/IPython/utils/_process_posix.py", line 23, in <module>
    import pexpect
  File "/usr/lib/python3/dist-packages/pexpect/__init__.py", line 75, in <module>
    from .pty_spawn import spawn, spawnu
  File "/usr/lib/python3/dist-packages/pexpect/pty_spawn.py", line 15, in <module>
    from .spawnbase import SpawnBase
  File "/usr/lib/python3/dist-packages/pexpect/spawnbase.py", line 218
    def expect(self, pattern, timeout=-1, searchwindowsize=-1, async=False):
                                                                   ^
SyntaxError: invalid syntax