Repository: scikit-hep/awkward

Issue:
ak.from_parquet for multiple files uses wrong number of arguments to concatenate
### Version of Awkward Array

2.0.0rc6

### Description and code to reproduce

If passing a directory with more than one file to `ak.from_parquet` the following exception is raised:

(the `outputs` directory in this example contains 50 files)

```python
In [4]: ak.from_parquet("outputs")
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
Cell In [4], line 1
----> 1 ak.from_parquet("outputs")

File ~/.pyenv/versions/3.10.8/envs/dev/lib/python3.10/site-packages/awkward/operations/ak_from_parquet.py:75, in from_parquet(path, columns, row_groups, storage_options, max_gap, max_block, footer_sample_size, generate_bitmasks, highlevel, behavior)
     67 import awkward._connect.pyarrow  # noqa: F401
     69 parquet_columns, subform, actual_paths, fs, subrg, row_counts, meta = metadata(
     70     path,
     71     storage_options,
     72     row_groups,
     73     columns,
     74 )
---> 75 return _load(
     76     actual_paths,
     77     parquet_columns if columns is not None else None,
     78     subrg,
     79     max_gap,
     80     max_block,
     81     footer_sample_size,
     82     generate_bitmasks,
     83     subform,
     84     highlevel,
     85     behavior,
     86     fs,
     87 )

File ~/.pyenv/versions/3.10.8/envs/dev/lib/python3.10/site-packages/awkward/operations/ak_from_parquet.py:246, in _load(actual_paths, parquet_columns, subrg, max_gap, max_block, footer_sample_size, generate_bitmasks, subform, highlevel, behavior, fs, metadata)
    243     return ak.Array(arrays[0])
    244 else:
    245     # TODO: if each array is a record?
--> 246     return ak.operations.ak_concatenate._impl(
    247         arrays, 0, True, True, highlevel, behavior
    248     )

TypeError: _impl() takes 5 positional arguments but 6 were given
```




Discussion:
cc @martindurant 
can be recreated with the following (`import awkward as ak` and `import dask_awkward as dak`)

```python
In [1]: ds = dak.from_parquet(
   ...:     "s3://ddavistemp/higgs_pq/*.parquet", storage_options={"anon": True}
   ...: )

In [2]: dak.to_parquet(ds, "outputs")

In [3]: !ls outputs
part00.parquet	part05.parquet	part10.parquet	part15.parquet	part20.parquet	part25.parquet	part30.parquet	part35.parquet	part40.parquet	part45.parquet
part01.parquet	part06.parquet	part11.parquet	part16.parquet	part21.parquet	part26.parquet	part31.parquet	part36.parquet	part41.parquet	part46.parquet
part02.parquet	part07.parquet	part12.parquet	part17.parquet	part22.parquet	part27.parquet	part32.parquet	part37.parquet	part42.parquet	part47.parquet
part03.parquet	part08.parquet	part13.parquet	part18.parquet	part23.parquet	part28.parquet	part33.parquet	part38.parquet	part43.parquet	part48.parquet
part04.parquet	part09.parquet	part14.parquet	part19.parquet	part24.parquet	part29.parquet	part34.parquet	part39.parquet	part44.parquet	part49.parquet

In [4]: ak.from_parquet("outputs")
```

Resolving patch:
diff --git a/src/awkward/operations/ak_from_parquet.py b/src/awkward/operations/ak_from_parquet.py
--- a/src/awkward/operations/ak_from_parquet.py
+++ b/src/awkward/operations/ak_from_parquet.py
@@ -244,7 +244,7 @@ def _load(
     else:
         # TODO: if each array is a record?
         return ak.operations.ak_concatenate._impl(
-            arrays, 0, True, True, highlevel, behavior
+            arrays, axis=0, mergebool=True, highlevel=highlevel, behavior=behavior
         )
 
 


Test patch: