how to read a text file as bytes

[Skaperen]

i want to read a file as a list of byte types, one for each line where '\n' or '\r' or '\r\n' or even the unlikely '\n\r' are marking end of line. the file might be so large that two copies of it in memory can exhaust memory so i need a way that is not "read in the whole file and do a big split". there are UTF-8 byte sequences with non-ASCII values in some of the files. i am using Python3. what is a good Pythonic way to no this? can the os module be avoided?