python selenium unknown error: DevToolsActivePort file doesn't exist

如果是crontab 执行 python selenium 的话 会出现一个因为环境变量引起的报错
(unknown error: DevToolsActivePort file doesn't exist)
(The process started from chrome location /usr/bin/google-chrome is no longer running, so ChromeDriver is assuming that Chrome has crashed.)
解决方案是命令行改成

export DISPLAY=:0.0 && /usr/local/bin/python3.7 /srv/project/manage.py report >> /var/log/csj_login.log # django-cronjobs for priject

在Linux/Unix类操作系统上, DISPLAY用来设置将图形显示到何处. 直接登陆图形界面或者登陆命令行界面后使用startx启动图形, DISPLAY环境变量将自动设置为:0:0, 此时可以打开终端, 输出图形程序的名称(比如xclock)来启动程序, 图形将显示在本地窗口上