blobs.py

def blobs(size, start=0):
    """Yield sequential blobs of bytes of the given size.

    >>> list(blobs(0))
    [b'']

    >>> b = blobs(1)
    >>> for _ in range(0x10):
    ...     print(' '.join(next(b).hex() for _ in range(0x10)))
    00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f
    10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f
    20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f
    30 31 32 33 34 35 36 37 38 39 3a 3b 3c 3d 3e 3f
    40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f
    50 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f
    60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f
    70 71 72 73 74 75 76 77 78 79 7a 7b 7c 7d 7e 7f
    80 81 82 83 84 85 86 87 88 89 8a 8b 8c 8d 8e 8f
    90 91 92 93 94 95 96 97 98 99 9a 9b 9c 9d 9e 9f
    a0 a1 a2 a3 a4 a5 a6 a7 a8 a9 aa ab ac ad ae af
    b0 b1 b2 b3 b4 b5 b6 b7 b8 b9 ba bb bc bd be bf
    c0 c1 c2 c3 c4 c5 c6 c7 c8 c9 ca cb cc cd ce cf
    d0 d1 d2 d3 d4 d5 d6 d7 d8 d9 da db dc dd de df
    e0 e1 e2 e3 e4 e5 e6 e7 e8 e9 ea eb ec ed ee ef
    f0 f1 f2 f3 f4 f5 f6 f7 f8 f9 fa fb fc fd fe ff

    >>> next(b)
    Traceback (most recent call last):
      ...
    StopIteration

    >>> for i in range(3):
    ...     print(len(list(blobs(i))))
    1
    256
    65536
    """
    from itertools import count
    for i in count(start):
        try:
            yield i.to_bytes(size, 'big')
        except OverflowError:
            break


def all_blobs(size=0, start=0):
    """Yield sequential blobs of bytes of sequential sizes.

    >>> b = all_blobs()
    >>> next(b).hex(), next(b).hex(), next(b).hex()
    ('', '00', '01')
    """
    from itertools import count
    for size in count(size):
        yield from blobs(size, start=start)