documentation for raw bytes

[Skaperen]

i have a few programs to write that i could have written in C and would have had no problems.  but i started writing them in Python3 and am running into the code conversion issues because a few of the bytes are above 127 in value.  and they are not all valid UTF-8.  they do not represent Unicode characters.  they are raw bytes.  they are what they are.  but Python3 gets upset over them.  i have been trying to read the documentation on this, but it is confusing.  i need to use bytes.  but many parts of Python just don't work with raw bytes as-is.  is there a document somewhere that explains bytes and how to use them much like you would in C so i don't have to switch back to C?

for example when i have:

for line in sys.stdin:
    do_something(line)

how can i have the value of line be bytes, even with some bytes > 127?