Recursively concatenate nested lists of arrays along axes Each entry in axes corresponds to each level of the nested list. The length of axes should correspond to the level of nesting of arrays. If axes is an empty list or tuple, return arrays, or arrays[0] if arrays is a list.
(arrays, axes=None)
| 376 | |
| 377 | |
| 378 | def _concatenate2(arrays, axes=None): |
| 379 | """Recursively concatenate nested lists of arrays along axes |
| 380 | |
| 381 | Each entry in axes corresponds to each level of the nested list. The |
| 382 | length of axes should correspond to the level of nesting of arrays. |
| 383 | If axes is an empty list or tuple, return arrays, or arrays[0] if |
| 384 | arrays is a list. |
| 385 | |
| 386 | >>> x = np.array([[1, 2], [3, 4]]) |
| 387 | >>> _concatenate2([x, x], axes=[0]) |
| 388 | array([[1, 2], |
| 389 | [3, 4], |
| 390 | [1, 2], |
| 391 | [3, 4]]) |
| 392 | |
| 393 | >>> _concatenate2([x, x], axes=[1]) |
| 394 | array([[1, 2, 1, 2], |
| 395 | [3, 4, 3, 4]]) |
| 396 | |
| 397 | >>> _concatenate2([[x, x], [x, x]], axes=[0, 1]) |
| 398 | array([[1, 2, 1, 2], |
| 399 | [3, 4, 3, 4], |
| 400 | [1, 2, 1, 2], |
| 401 | [3, 4, 3, 4]]) |
| 402 | |
| 403 | Supports Iterators |
| 404 | >>> _concatenate2(iter([x, x]), axes=[1]) |
| 405 | array([[1, 2, 1, 2], |
| 406 | [3, 4, 3, 4]]) |
| 407 | |
| 408 | Special Case |
| 409 | >>> _concatenate2([x, x], axes=()) |
| 410 | array([[1, 2], |
| 411 | [3, 4]]) |
| 412 | """ |
| 413 | if axes is None: |
| 414 | axes = [] |
| 415 | |
| 416 | if axes == (): |
| 417 | if isinstance(arrays, list): |
| 418 | return arrays[0] |
| 419 | else: |
| 420 | return arrays |
| 421 | |
| 422 | if isinstance(arrays, Iterator): |
| 423 | arrays = list(arrays) |
| 424 | if not isinstance(arrays, (list, tuple)): |
| 425 | return arrays |
| 426 | if len(axes) > 1: |
| 427 | arrays = [_concatenate2(a, axes=axes[1:]) for a in arrays] |
| 428 | concatenate = concatenate_lookup.dispatch( |
| 429 | type(max(arrays, key=lambda x: getattr(x, "__array_priority__", 0))) |
| 430 | ) |
| 431 | if isinstance(arrays[0], dict): |
| 432 | # Handle concatenation of `dict`s, used as a replacement for structured |
| 433 | # arrays when that's not supported by the array library (e.g., CuPy). |
| 434 | keys = list(arrays[0].keys()) |
| 435 | assert all(list(a.keys()) == keys for a in arrays) |
no test coverage detected