Enforce dtype=object for incompatible numpy array conversion

[bnavigator]

Numpy 1.24 does not accept ragged sequences without dtype=object anymore: numpy/numpy#22004

Fixes #333

Before (#333 (comment) and #416):

[   51s] ____________________________ test_non_numpy_inputs _____________________________
[   51s] 
[   51s]     def test_non_numpy_inputs():
[   51s]         # numpy will infer a range of different shapes and dtypes for these inputs.
[   51s]         # Make sure that round-tripping through encode preserves this.
[   51s]         data = [
[   51s]             [0, 1],
[   51s]             [[0, 1], [2, 3]],
[   51s]             [[0], [1], [2, 3]],
[   51s]             [[[0, 0]], [[1, 1]], [[2, 3]]],
[   51s]             ["1"],
[   51s]             ["11", "11"],
[   51s]             ["11", "1", "1"],
[   51s]             [{}],
[   51s]             [{"key": "value"}, ["list", "of", "strings"]],
[   51s]         ]
[   51s]         for input_data in data:
[   51s]             for codec in codecs:
[   51s] >               output_data = codec.decode(codec.encode(input_data))
[   51s] 
[   51s] ../../BUILDROOT/python-numcodecs-0.11.0-0.x86_64/usr/lib64/python3.8/site-packages/numcodecs/tests/test_json.py:72: 
[   51s] _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
[   51s] 
[   51s] self = JSON(encoding='utf-8', allow_nan=True, check_circular=True, ensure_ascii=True,
[   51s]      indent=None, separators=(',', ':'), skipkeys=False, sort_keys=True,
[   51s]      strict=True)
[   51s] buf = [[0], [1], [2, 3]]
[   51s] 
[   51s]     def encode(self, buf):
[   51s] >       buf = np.asarray(buf)
[   51s] E       ValueError: setting an array element with a sequence. The requested array has an inhomogeneous shape after 1 dimensions. The detected shape was (3,) + inhomogeneous part.
[   51s] 
[   51s] ../../BUILDROOT/python-numcodecs-0.11.0-0.x86_64/usr/lib64/python3.8/site-packages/numcodecs/json.py:57: ValueError
[   51s] ____________________________ test_non_numpy_inputs _____________________________
[   51s] 
[   51s]     def test_non_numpy_inputs():
[   51s]         codec = MsgPack()
[   51s]         # numpy will infer a range of different shapes and dtypes for these inputs.
[   51s]         # Make sure that round-tripping through encode preserves this.
[   51s]         data = [
[   51s]             [0, 1],
[   51s]             [[0, 1], [2, 3]],
[   51s]             [[0], [1], [2, 3]],
[   51s]             [[[0, 0]], [[1, 1]], [[2, 3]]],
[   51s]             ["1"],
[   51s]             ["11", "11"],
[   51s]             ["11", "1", "1"],
[   51s]             [{}],
[   51s]             [{"key": "value"}, ["list", "of", "strings"]],
[   51s]             [b"1"],
[   51s]             [b"11", b"11"],
[   51s]             [b"11", b"1", b"1"],
[   51s]             [{b"key": b"value"}, [b"list", b"of", b"strings"]],
[   51s]         ]
[   51s]         for input_data in data:
[   51s] >           actual = codec.decode(codec.encode(input_data))
[   51s] 
[   51s] ../../BUILDROOT/python-numcodecs-0.11.0-0.x86_64/usr/lib64/python3.8/site-packages/numcodecs/tests/test_msgpacks.py:75: 
[   51s] _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
[   51s] 
[   51s] self = MsgPack(raw=False, use_bin_type=True, use_single_float=False)
[   51s] buf = [[0], [1], [2, 3]]
[   51s] 
[   51s]     def encode(self, buf):
[   51s] >       buf = np.asarray(buf)
[   51s] E       ValueError: setting an array element with a sequence. The requested array has an inhomogeneous shape after 1 dimensions. The detected shape was (3,) + inhomogeneous part.
[   51s] 
[   51s] ../../BUILDROOT/python-numcodecs-0.11.0-0.x86_64/usr/lib64/python3.8/site-packages/numcodecs/msgpacks.py:55: ValueError

[codecov]

Codecov Report

Merging #417 (bee8aa7) into main (955019b) will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##              main      #417   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           54        54           
  Lines         2089      2095    +6     
=========================================
+ Hits          2089      2095    +6     

Impacted Files	Coverage Δ
numcodecs/json.py	100.00% <100.00%> (ø)
numcodecs/msgpacks.py	100.00% <100.00%> (ø)
numcodecs/tests/test_json.py	100.00% <100.00%> (ø)
numcodecs/tests/test_msgpacks.py	100.00% <100.00%> (ø)

[martindurant]

+1 from me. Will merge unless someone objects.

[martindurant]

Thanks, @bnavigator

[joshmoore]

+1 from me. Will merge unless someone objects.

Still catching up after the holidays. Probably my only concern is that with v3 we probably want a more explicit handle on when object is permissible, but that's a lot longer-term than numpy 1.24 which is here now.