A error while updating

[aalekh641]

Traceback (most recent call last):
File "/home/kali/CloudFail/cloudfail.py", line 302, in
update()
File "/home/kali/CloudFail/cloudfail.py", line 249, in update
with open('data/cf-subnet.txt', 'wb') as fd:
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
PermissionError: [Errno 13] Permission denied: 'data/cf-subnet.txt'