Oops, a server error has occured "ImportError: No module named ldap"

When try to open the site I got the error message above. I reinstall the bench but same message again. Update also no help. Here is detail. What should I do?

Traceback (most recent call last):
File “/home/catman/frappe-bench/apps/frappe/frappe/website/render.py”, line 32, in render
data = render_page_by_language(path)
File “/home/catman/frappe-bench/apps/frappe/frappe/website/render.py”, line 101, in render_page_by_language
return render_page(path)
File “/home/catman/frappe-bench/apps/frappe/frappe/website/render.py”, line 117, in render_page
return build(path)
File “/home/catman/frappe-bench/apps/frappe/frappe/website/render.py”, line 124, in build
return build_page(path)
File “/home/catman/frappe-bench/apps/frappe/frappe/website/render.py”, line 137, in build_page
context = get_context(path)
File “/home/catman/frappe-bench/apps/frappe/frappe/website/context.py”, line 19, in get_context
context = build_context(context)
File “/home/catman/frappe-bench/apps/frappe/frappe/website/context.py”, line 65, in build_context
module = frappe.get_module(context.controller)
File “/home/catman/frappe-bench/apps/frappe/frappe/init.py”, line 646, in get_module
return importlib.import_module(modulename)
File “/usr/lib/python2.7/importlib/init.py”, line 37, in import_module
File “/home/catman/frappe-bench/apps/frappe/frappe/www/login.py”, line 11, in
from frappe.integrations.ldap_auth import get_ldap_settings
File “/home/catman/frappe-bench/apps/frappe/frappe/integrations/ldap_auth.py”, line 2, in
import ldap, json
ImportError: No module named ldap

are you update erpnext develop or production?
if you use erpnext production, before you update, switch-to-master first

frappe-bench$ bench switch-to-master
frappe-bench$ bench update

if, you get error again
try this.
frappe-bench$ bench remove-from-installed-apps ldap
frappe-bench$ bench migrate

Thank You komsel2228,
I have already deleted all the folders including frappe bench, removed all users in MariaDB database and installed it again. However, thank you very much for the help.