Use auto rechunking in da.rechunk if no value given

mrocklin · Nov 19, 2019 · 1f4a00c · 1f4a00c
1 parent 7967652
commit 1f4a00c
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Showing 3 changed files with 9 additions and 2 deletions.
diff --git a/dask/array/core.py b/dask/array/core.py
@@ -2164,7 +2164,7 @@ def squeeze(self, axis=None):
 
         return squeeze(self, axis)
 
-    def rechunk(self, chunks, threshold=None, block_size_limit=None):
+    def rechunk(self, chunks="auto", threshold=None, block_size_limit=None):
         """ See da.rechunk for docstring """
         from . import rechunk  # avoid circular import
 

diff --git a/dask/array/rechunk.py b/dask/array/rechunk.py
@@ -181,7 +181,7 @@ def intersect_chunks(old_chunks, new_chunks):
     return cross
 
 
-def rechunk(x, chunks, threshold=None, block_size_limit=None):
+def rechunk(x, chunks="auto", threshold=None, block_size_limit=None):
     """
     Convert blocks in dask array x for new chunks.
 

diff --git a/dask/array/tests/test_array_core.py b/dask/array/tests/test_array_core.py
@@ -4224,3 +4224,10 @@ def test_compute_chunk_sizes_warning_fixes_slicing():
         y[:3, :]
     y.compute_chunk_sizes()
     y[:3, :]
+
+
+def test_rechunk_auto():
+    x = da.ones(10, chunks=(1,))
+    y = x.rechunk()
+
+    assert y.npartitions == 1