报错信息：
[root@localhost bin]# systemctl status firewalld
● firewalld.service - firewalld - dynamic firewall daemon
Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled; vendor preset: enabled)
Active: failed (Result: exit-code) since Fri 2019-01-25 02:07:03 EST; 4min 25s ago
Docs: man:firewalld(1)
Process: 2037 ExecStart=/usr/sbin/firewalld --nofork --nopid $FIREWALLD_ARGS (code=exited, status=127)
Main PID: 2037 (code=exited, status=127)
Jan 25 02:07:03 localhost.localdomain systemd[1]: Starting firewalld - dynamic firewall daemon...
Jan 25 02:07:03 localhost.localdomain systemd[1]: firewalld.service: main process exited, code=exited, status=127/n/a
Jan 25 02:07:03 localhost.localdomain systemd[1]: Failed to start firewalld - dynamic firewall daemon.
Jan 25 02:07:03 localhost.localdomain systemd[1]: Unit firewalld.service entered failed state.
Jan 25 02:07:03 localhost.localdomain systemd[1]: firewalld.service failed.
gogle了一大堆，一个老兄说python版本不对。我的python确实从2升到3了
解决办法
1 查看firewalld在那个路径下
which firewalld
2 编辑firewalld文件
3 将这个声明，改为你老版本python。