How to I define a variable between strings in telnetlib write?

[Fez]

How to I use a variable in telnetlib write? I can get connected no problem. I am new to python.

for line in  ipaddress:

 Host=line.strip("\n")    
 file = Host
 
 connection.write(b"save configuration network" + file +  "1.1.1.1 \n")

I am setting file equal Host IP. This gives me an error stating I cannot concat a string to bytes. So file will chnage for every Host in ipaddress file. If I remove the '+' signs in line and one pair of double quotes, I get a backup file but the name is file.

Error:
Traceback (most recent call last):
  File "C:\python_scripts\Backup_multi_lx.py", line 32, in <module>
    connection.write(b"save configuration network" + file +  "10.2.99.91 \n")
TypeError: can't concat str to bytes

[nilamo]

>>> file = "some string"
>>> output = b"save configuration network"
>>>
>>> # you can encode the string, which turns it into bytes...
...
>>> file.encode()
b'some string'
>>> # which would then be used like...
...
>>> output + file.encode()
b'save configuration networksome string'

[Fez]

Thanks for the help, but I figured a way around it. I used the word file so backup is called file.zip and I used os.rename() to rename it to the IP address of the device.