creating python virtualenv 一直显示语法错误

Question

在centos7上成功安装virtualenv后

pip install virtualenv

在创建新的 virtualenv 时它一直显示下面提到的错误，即使我正在检查

virtualenv --version

这也显示了同样的错误。

Traceback (most recent call last):
  File "/usr/bin/virtualenv", line 7, in <module>
    from virtualenv.__main__ import run_with_catch
  File "/usr/lib/python2.7/site-packages/virtualenv/__init__.py", line 3, in <module>
    from .run import cli_run
  File "/usr/lib/python2.7/site-packages/virtualenv/run/__init__.py", line 12, in <module>
    from .plugin.activators import ActivationSelector
  File "/usr/lib/python2.7/site-packages/virtualenv/run/plugin/activators.py", line 6, in <module>
    from .base import ComponentBuilder
  File "/usr/lib/python2.7/site-packages/virtualenv/run/plugin/base.py", line 9, in <module>
    from importlib_metadata import entry_points
  File "/usr/lib/python2.7/site-packages/importlib_metadata/__init__.py", line 9, in <module>
    import zipp
  File "/usr/lib/python2.7/site-packages/zipp.py", line 153
SyntaxError: Non-ASCII character '\xe2' in file /usr/lib/python2.7/site-packages/zipp.py on line 154, but no encoding declared; see http://www.python.org/peps/pep-0263.html for details

我尝试卸载并重新安装它，但到目前为止没有成功。

Answer 1

您正在使用 Python 2.7（已停产）和不支持 Python 2.7 的 Virtualenv 版本。

按优先顺序排列，

停止使用 Python 2.7 并使用 Python 3.x（当前为 3.8）
或安装旧版本的 Virtualenv（例如 pip install "virtualenv<20.0"，或任何最终适合你的 Virtualenv 主要版本）。

Answer 2

在我的例子中，当运行 workon <foo>:

时，我得到了类似的错误

xb@dnxb:/tmp$ workon foo
Traceback (most recent call last):
  File "/usr/lib/python2.7/runpy.py", line 174, in _run_module_as_main
    "__main__", fname, loader, pkg_name)
  File "/usr/lib/python2.7/runpy.py", line 72, in _run_code
    exec code in run_globals
  File "/home/xiaobai/.local/lib/python3.6/site-packages/virtualenvwrapper/hook_loader.py", line 16, in <module>
    from stevedore import ExtensionManager
  File "/home/xiaobai/.local/lib/python3.6/site-packages/stevedore/__init__.py", line 11, in <module>
    from .extension import ExtensionManager
  File "/home/xiaobai/.local/lib/python3.6/site-packages/stevedore/extension.py", line 19, in <module>
    from . import _cache
  File "/home/xiaobai/.local/lib/python3.6/site-packages/stevedore/_cache.py", line 31, in <module>
    import importlib_metadata
  File "/home/xiaobai/.local/lib/python3.6/site-packages/importlib_metadata/__init__.py", line 9, in <module>
    import zipp
  File "/home/xiaobai/.local/lib/python3.6/site-packages/zipp.py", line 153
SyntaxError: Non-ASCII character '\xe2' in file /home/xiaobai/.local/lib/python3.6/site-packages/zipp.py on line 154, but no encoding declared; see http://python.org/dev/peps/pep-0263/ for details
...

开头显示python2.7/runpy.py的错误，但我希望在整个过程中使用python 3。

然后我在 source /usr/share/virtualenvwrapper/virtualenvwrapper.sh 时也得到同样的错误。

所以我检查文件并注意到它使用 python 2 基于 which python 命令的结果，/usr/bin/python 符号链接到我系统中的 python2.7：

xb@dnxb:/tmp$ grep -n which /usr/share/virtualenvwrapper/virtualenvwrapper.sh
50:    VIRTUALENVWRAPPER_PYTHON="$(command \which python)"
316:    typeset exe_path="$(command \which "" | (unset GREP_OPTIONS; command \grep -v "not found"))"
xb@dnxb:/tmp$ which python
/usr/bin/python

所以只需将此行编辑为 hard-coded 路径 /usr/bin/python3（我的 python3 路径），source 或 workon 都不会再出现错误：

xb@dnxb:/tmp$ sudo sed -i 's/VIRTUALENVWRAPPER_PYTHON="$(command \which python)"/VIRTUALENVWRAPPER_PYTHON=\/usr\/bin\/python3/g' /usr/share/virtualenvwrapper/virtualenvwrapper.sh
xb@dnxb:/tmp$ grep -n which /usr/share/virtualenvwrapper/virtualenvwrapper.sh
316:    typeset exe_path="$(command \which "" | (unset GREP_OPTIONS; command \grep -v "not found"))"
xb@dnxb:/tmp$ grep -n python3 /usr/share/virtualenvwrapper/virtualenvwrapper.sh
50:    VIRTUALENVWRAPPER_PYTHON=/usr/bin/python3
xb@dnxb:/tmp$ workon foo
(foo) xb@dnxb:/tmp$

当然，如果您想在不编辑此脚本的情况下动态使用 python 2 或 3，您可以设置 VIRTUALENVWRAPPER_PYTHON 环境变量。

creating python virtualenv 一直显示语法错误

creating python virtualenv keep showing error of syntax

python

virtualenv