Why so complicated?

[wavic]

The last message doesn't mean that the packet is not installed. This is happening when you pip install using sudo.

For example:

$ sudo python3.5 -m pip install -U scapy-python3

Output:
The directory '/home/victor/.cache/pip/http' or its parent directory is not owned by the current user and the cache has been disabled. Please check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag.
The directory '/home/victor/.cache/pip' or its parent directory is not owned by the current user and caching wheels has been disabled. check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag.
Requirement already up-to-date: scapy-python3 in /usr/local/lib/python3.5/dist-packages