How to install python-serial?

Question

linux

I have a python web server that should use serial
Apache and MySQL server and phpmyadmin are also running. Trying

to install python-serial gives an error

Reading package lists... Done
Building dependency tree
Reading state information... Done
python-serial is already the newest version (3.4-4).
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
1 not fully installed or removed.
After this operation, 0 B of additional disk space will be used.
Do you want to continue? [Y/n] y
Setting up nginx-full (1.14.2-2+deb10u3) ...
Job for nginx.service failed because the control process exited with error code.
See "systemctl status nginx.service" and "journalctl -xe" for details.
invoke-rc.d: initscript nginx, action "start" failed.
● nginx.service - A high performance web server and a reverse proxy server
Loaded: loaded (/lib/systemd/system/nginx.service; enabled; vendor preset: enabled)
Active: failed (Result: exit-code) since Thu 2020-10-29 13:27:07 GMT; 56ms ago
Docs: man:nginx(8)
Process: 940 ExecStartPre=/usr/sbin/nginx -t -q -g daemon on; master_process on; (code=exited, status=1/FAILURE)

Oct 29 13:27:07 pi systemd[1]: Starting A high performance web server and a reverse proxy server...
Oct 29 13:27:07 pi nginx[940] : nginx: [emerg] "fastcgi_pass" directive is duplicate in /etc/nginx/sites-enabled/default:62
Oct 29 13:27:07 pi nginx[940]: nginx: configuration file /etc/nginx/nginx.conf test failed
Oct 29 13:27:07 pi systemd[1]: nginx.service: Control process exited, code=exited, status=1/FAILURE
Oct 29 13:27:07 pi systemd[1]: nginx.service: Failed with result 'exit-code'.
Oct 29 13:27:07 pi systemd[1]: Failed to start A high performance web server and a reverse proxy server.
dpkg: error processing package nginx-full (--configure):
installed nginx-full package post-installation script subprocess returned error exit status 1
Errors were encountered while processing:
nginx-full
E: Sub-process /usr/bin/dpkg returned an error code (1)

It seems that the port is just busy, but I'm in no hurry to kill the processes. don't know how python-serial works Does
it need ports just for installation? Or will he take them in the future? What to do?