no flask module error

erro.log

 sudo tail -10 /var/log/apache2/error.log
[Fri Aug 31 17:37:34.551181 2018] [mpm_event:notice] [pid 18421:tid 139974958294912] AH00489: Apache/2.4.18 (Ubuntu) mod_wsgi/4.3.0 Python/2.7.12 configured -- resuming normal operations
[Fri Aug 31 17:37:34.551199 2018] [core:notice] [pid 18421:tid 139974958294912] AH00094: Command line: '/usr/sbin/apache2'
[Fri Aug 31 17:37:43.778862 2018] [wsgi:error] [pid 18425:tid 139974687041280] [client 197.255.174.176:20682] mod_wsgi (pid=18425): Target WSGI script '/var/www/catalogApp/catalog/catalog.wsgi' cannot be loaded as Python module.
[Fri Aug 31 17:37:43.778889 2018] [wsgi:error] [pid 18425:tid 139974687041280] [client 197.255.174.176:20682] mod_wsgi (pid=18425): Exception occurred processing WSGI script '/var/www/catalogApp/catalog/catalog.wsgi'.
[Fri Aug 31 17:37:43.778911 2018] [wsgi:error] [pid 18425:tid 139974687041280] [client 197.255.174.176:20682] Traceback (most recent call last):
[Fri Aug 31 17:37:43.778926 2018] [wsgi:error] [pid 18425:tid 139974687041280] [client 197.255.174.176:20682]   File "/var/www/catalogApp/catalog/catalog.wsgi", line 7, in <module>
[Fri Aug 31 17:37:43.778964 2018] [wsgi:error] [pid 18425:tid 139974687041280] [client 197.255.174.176:20682]     from application.py import app as application
[Fri Aug 31 17:37:43.778973 2018] [wsgi:error] [pid 18425:tid 139974687041280] [client 197.255.174.176:20682]   File "/var/www/catalogApp/catalog/application.py", line 2, in <module>
[Fri Aug 31 17:37:43.779056 2018] [wsgi:error] [pid 18425:tid 139974687041280] [client 197.255.174.176:20682]     from flask import Flask, render_template, request, redirect
[Fri Aug 31 17:37:43.779070 2018] [wsgi:error] [pid 18425:tid 139974687041280] [client 197.255.174.176:20682] ImportError: No module named flask