ubuntu 将目录添加到 PYTHONPATH 会导致我的主目录也被添加

新用户34008MEn 2021-07-14

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我尝试/home/myname/bin通过将以下内容插入到我的 PYTHONPATH 中来将该目录添加到我的 PYTHONPATH 中.bashrc：

if [ -d ~/bin ]; thenexport PYTHONPATH=$PYTHONPATH:/home/myname/binfi

不幸的是，这似乎将我的主目录添加到 Python 的搜索路径中，如在 Python 中运行以下命令所示：

>>> import sys>>> sys.path['', '/home/myname', '/home/myname/bin', '/usr/lib/python3.4', '/usr/lib/python3.4/plat-x86_64-linux-gnu', '/usr/lib/python3.4/lib-dynload', '/usr/local/lib/python3.4/dist-packages', '/usr/lib/python3/dist-packages']

请注意，echo $PYTHONPATH只是返回:/home/myname/bin.

问题是您包含了的现有值PYTHONPATH。但是，该变量未设置，因此其计算结果为空字符串。出于某种原因，这似乎python包括您的$HOME目录。据推测，这是默认目录：

$ python -c 'import sys; print sys.path'['', '/usr/lib/python2.7', '/usr/lib/python2.7/plat-x86_64-linux-gnu', '/usr/lib/python2.7/lib-tk', '/usr/lib/python2.7/lib-old', '/usr/lib/python2.7/lib-dynload', '/usr/local/lib/python2.7/dist-packages', '/usr/lib/python2.7/dist-packages', '/usr/lib/python2.7/dist-packages/PILcompat', '/usr/lib/python2.7/dist-packages/gst-0.10', '/usr/lib/python2.7/dist-packages/gtk-2.0', '/usr/lib/pymodules/python2.7', '/usr/lib/python2.7/dist-packages/wx-3.0-gtk2']

但是，如果我设置PYTHONPATH为空字符串，$HOME则包括my ：

$ PYTHONPATH=""; python -c 'import sys; print sys.path'['', '/home/terdon', '/usr/lib/python2.7', '/usr/lib/python2.7/plat-x86_64-linux-gnu', '/usr/lib/python2.7/lib-tk', '/usr/lib/python2.7/lib-old', '/usr/lib/python2.7/lib-dynload', '/usr/local/lib/python2.7/dist-packages', '/usr/lib/python2.7/dist-packages', '/usr/lib/python2.7/dist-packages/PILcompat', '/usr/lib/python2.7/dist-packages/gst-0.10', '/usr/lib/python2.7/dist-packages/gtk-2.0', '/usr/lib/pymodules/python2.7', '/usr/lib/python2.7/dist-packages/wx-3.0-gtk2']

因此，当您PYTHONPATH在设置时包含当前值时，这就是您得到的行为：

$ PYTHONPATH="$PYTHONPATH:$HOME/bin" python -c 'import sys; print sys.path'['', '/home/terdon', '/home/terdon/bin', '/usr/lib/python2.7', '/usr/lib/python2.7/plat-x86_64-linux-gnu', '/usr/lib/python2.7/lib-tk', '/usr/lib/python2.7/lib-old', '/usr/lib/python2.7/lib-dynload', '/usr/local/lib/python2.7/dist-packages', '/usr/lib/python2.7/dist-packages', '/usr/lib/python2.7/dist-packages/PILcompat', '/usr/lib/python2.7/dist-packages/gst-0.10', '/usr/lib/python2.7/dist-packages/gtk-2.0', '/usr/lib/pymodules/python2.7', '/usr/lib/python2.7/dist-packages/wx-3.0-gtk2']

设置它的正确方法是只给它你要添加的目录：

$ PYTHONPATH="$HOME/bin" python -c 'import sys; print sys.path'['', '/home/terdon/bin', '/usr/lib/python2.7', '/usr/lib/python2.7/plat-x86_64-linux-gnu', '/usr/lib/python2.7/lib-tk', '/usr/lib/python2.7/lib-old', '/usr/lib/python2.7/lib-dynload', '/usr/local/lib/python2.7/dist-packages', '/usr/lib/python2.7/dist-packages', '/usr/lib/python2.7/dist-packages/PILcompat', '/usr/lib/python2.7/dist-packages/gst-0.10', '/usr/lib/python2.7/dist-packages/gtk-2.0', '/usr/lib/pymodules/python2.7', '/usr/lib/python2.7/dist-packages/wx-3.0-gtk2']

或者，为了安全起见，以防它被定义，检查它是否为空并采取相应措施：

if [ -d ~/bin ]; then[ -z "$PYTHONPATH" ] && export PYTHONPATH="/home/myname/bin" ||export PYTHONPATH="$PYTHONPATH:/home/myname/bin"fi