Unable to execute python script through application which works and executes manually

Issue

• Prepared the script to start the application which is not working.
• But when the script was started manually, it is working.
• The command is

./host.py 9000 &

• Below is the script, which is not working

[root@localhost ~] # cat startKey.sh
#!/usr/bin/python
APP_DIR=/var/test
cd ${APP_DIR}
./host.py 9000 2>&1