fromstring is removed in python 3.9

[mnumanuyar]

fromstring is removed from python 3.9. (changelog)
related issue: python/cpython#83097

currently mavutil has an instance of it

pymavlink/mavutil.py

Line 2286 in ebc4bd4

byte_buf.fromstring(buf)

running it produces error:
"'array.array' object has no attribute 'fromstring' python"

I changed the line as

            if type(buf) == bytes: 
                byte_buf.frombytes(buf)
            elif type(buf) == str: 
                byte_buf.fromlist(list(buf.encode('utf8')))

in my local, which solved error. But I have no clue if this is correct, and I have not tested it well

[alehed]

This error should have been resolved by #666 which is now merged.

[mnumanuyar]

that line is still in the master branch, did the merge somehow made that line unaccesible ?

pymavlink/mavutil.py

Line 2296 in 7d5174f

byte_buf.fromstring(buf)

[alehed]

Ah, true. I was thinking about the generated code.