Running Nessus_Activation_Code.py throw a multiple errors

[armdn]

from: can't read /var/mail/bs4
./Nessus_Activation_Code.py: line 2: import: command not found
./Nessus_Activation_Code.py: line 3: import: command not found
./Nessus_Activation_Code.py: line 4: import: command not found
from: can't read /var/mail/tempmail
./Nessus_Activation_Code.py: line 6: import: command not found
./Nessus_Activation_Code.py: line 7: import: command not found
./Nessus_Activation_Code.py: line 9: syntax error near unexpected token (' ./Nessus_Activation_Code.py: line 9: def banner():'