我在 MacOS 上。我的默认 Python 是从 Python 2.7.15 的 brew 安装创建的虚拟环境。我的PATH设置为 venv 是默认的python。python2.7我在安装 gcloud 时遇到了一些问题，这些问题已解决，并且我已成功安装 gcloud。

但是，任何时候我尝试运行任何gcloud命令时，我仍然会得到安装时看到的相同的 ImportError。

Traceback (most recent call last):
  File "/path_to_gcloudsdk/google-cloud-sdk/lib/gcloud.py", line 20, in <module>
    from __future__ import absolute_import
ImportError: No module named __future__

每条评论请求的附加信息：

当我进入我的默认 python 解释器并运行时输出import sys; print(sys.path)：

[
    ''
    '/path_to_virtual_env/lib/python27.zip'
    '/path_to_virtual_env/lib/python2.7'
    '/path_to_virtual_env/lib/python2.7/plat-darwin'
    '/path_to_virtual_env/lib/python2.7/plat-mac'
    '/path_to_virtual_env/lib/python2.7/plat-mac/lib-scriptpackages'
    '/path_to_virtual_env/lib/python2.7/lib-tk'
    '/path_to_virtual_env/lib/python2.7/lib-old'
    '/path_to_virtual_env/lib/python2.7/lib-dynload'
    '/usr/local/Cellar/python@2/2.7.15_1/Frameworks/Python.framework/Versions/2.7/lib/python2.7'
    '/usr/local/Cellar/python@2/2.7.15_1/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-darwin'
    '/usr/local/Cellar/python@2/2.7.15_1/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-tk'
    '/usr/local/Cellar/python@2/2.7.15_1/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-mac'
    '/usr/local/Cellar/python@2/2.7.15_1/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-mac/lib-scriptpackages'
    '/path_to_virtual_env/lib/python2.7/site-packages'
]