This is not the solution I was after, but this is the solution I ended up with:
def process_binary_files(list_of_binary_files):
for file in list_of_binary_files:
with open(file,'rb') as f:
yield f.read(1)
return
list_of_binary_files = ['f1', 'f2']
generate_byte = process_binary_files(list_of_binary_files)
byte = next(generate_byte)