add .split_every() and .transpose() methods

binapy/binapy.py

@@ -6,6 +6,7 @@
 import secrets
 from contextlib import suppress
 from functools import wraps
+from itertools import zip_longest
 from typing import (
  Any,
  Callable,
@@ -339,6 +340,38 @@ def split_at(self, *pos: int) -> tuple[BinaPy, ...]:
 
  cut_at = split_at # for backward compatibility
 
+ def split_every(self, n: int, filler: bytes = b"") -> tuple[BinaPy, ...]:
+ """Split this BinaPy into chunks of size `n`.
+
+ If filler is b'' (default), last chunk may be smaller than `n`.
+ Use a single char bytes instead for equally sized chunks.
+
+ Args:
+ n: size of chunks
+ filler: char to use to fill the last chunk
+
+ Returns:
+ a tuple of `len(self)/n` (rounded up) items.
+
+ """
+ div, mod = divmod(len(self), n)
+ if div == 0:
+ return (self + filler * (n - len(self)),)
+ if mod == 0:
+ return self.split_at(*range(n, len(self), n))
+ chunks = self.split_at(*range(n, len(self), n))
+ return *chunks[:-1], chunks[-1] + filler * (n - mod)
+
+ def transpose(self, n: int, filler: bytes = b"") -> BinaPy:
+ """Reorder this BinaPy bytes from lines to columns."""
+
+ def iter_chunks() -> Iterator[bytes]:
+ lines = self.split_every(n, filler=filler)
+ for column in zip_longest(*lines):
+ yield bytes(c for c in column if c is not None)
+
+ return BinaPy(b"".join(iter_chunks()))
+
  extensions: ClassVar[dict[str, dict[str, Callable[..., Any]]]] = {}
  """Extension registry."""
 

tests/test_binapy.py

@@ -62,6 +62,13 @@ def test_binapy() -> None:
 
  assert BinaPy.serialize_to("json", JSON).parse_from("json") == JSON
 
+ assert BinaPy("0123456789").split_at(3,5,8) == (b"012", b"34", b"567", b'89')
+ assert BinaPy("0123456789").split_every(4) == (b"0123", b"4567", b"89")
+ assert BinaPy("0123456789").split_every(12) == (b"0123456789",)
+ assert BinaPy("0123456789").split_every(4, filler=b' ') == (b"0123", b"4567", b"89 ")
+
+ assert BinaPy("0123456789").transpose(3) == b"0369147258"
+ assert BinaPy("0123456789").transpose(3, filler=b' ') == b"0369147 258 "
 
 def test_slicing() -> None:
  bp = BinaPy("1234567890")