python read file as bytes

1#for small file:
2file = open("sample.bin", "rb")
3byte = file.read(1)
4while byte:
5    #do somthing with the byte
6    byte = file.read(1)
7file.close()
8
9#-------------------------------
10
11#for big file (biger the the memory):
12def bytes_from_file(filename, chunksize=8192): #8192 Byte = 8 kB (kib)
13    with open(filename, "rb") as f:
14        while True:
15            chunk = f.read(chunksize)
16            if chunk:
17                for b in chunk:
18                    yield b
19            else:
20                break
21
22#call it
23for b in bytes_from_file('filename'):
24    do_stuff_with(b)