From bf78f2c36460b6537914d098161e0be233d6ea27 Mon Sep 17 00:00:00 2001
From: Bas Nijholt <bas@nijho.lt>
Date: Fri, 11 Apr 2025 15:28:01 -0700
Subject: [PATCH 1/2] BUG: Fix display with nested arrays

Currently, the following will fail to display:
```python
import xarray as xr
import numpy as np
x = np.empty((2, 2), dtype=object)
for i in range(2):
    for j in range(2):
        x[i, j] = np.zeros(2)  # Set to 1D array of size 2
ds = xr.DataArray(x)
ds
```

Whenever there are `size==1` arrays, it currently does work:
```python
import xarray as xr
import numpy as np
x = np.empty((2, 2), dtype=object)
for i in range(2):
    for j in range(2):
        x[i, j] = np.zeros((1, 1, 1))  # Set to 3D array of size 1
ds = xr.DataArray(x)
ds

For context, I am running into this issue in https://github.com/pipefunc/pipefunc where one can put the resulting objects into `xarray.Dataset`s.
For example, see the docs here https://pipefunc.readthedocs.io/en/latest/examples/physics-simulation/ (search for `xarray.Dataset`).
---
 xarray/core/formatting.py       | 2 +-
 xarray/tests/test_formatting.py | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/xarray/core/formatting.py b/xarray/core/formatting.py
index 993cddf2b57..7088bd40a06 100644
--- a/xarray/core/formatting.py
+++ b/xarray/core/formatting.py
@@ -184,7 +184,7 @@ def format_item(x, timedelta_format=None, quote_strings=True):
         if hasattr(x, "dtype"):
             x = x.item()
         return repr(x) if quote_strings else x
-    elif hasattr(x, "dtype") and np.issubdtype(x.dtype, np.floating):
+    elif hasattr(x, "dtype") and np.issubdtype(x.dtype, np.floating) and x.size == 1:
         return f"{x.item():.4}"
     else:
         return str(x)
diff --git a/xarray/tests/test_formatting.py b/xarray/tests/test_formatting.py
index 2e0925c1b9a..a9c6852173e 100644
--- a/xarray/tests/test_formatting.py
+++ b/xarray/tests/test_formatting.py
@@ -101,6 +101,8 @@ def test_format_item(self) -> None:
             (np.float16(1.1234), "1.123"),
             (np.float32(1.0111111), "1.011"),
             (np.float64(22.222222), "22.22"),
+            (np.zeros((1, 1)), "0.0"),
+            (np.zeros(2), "[0. 0.]"),
         ]
         for item, expected in cases:
             actual = formatting.format_item(item)

From 4fef1ba84365c63f16d740c13b37b66111069c3a Mon Sep 17 00:00:00 2001
From: Bas Nijholt <bas@nijho.lt>
Date: Fri, 11 Apr 2025 15:41:05 -0700
Subject: [PATCH 2/2] Add additional test case

---
 xarray/tests/test_formatting.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/xarray/tests/test_formatting.py b/xarray/tests/test_formatting.py
index a9c6852173e..dce1528c7ae 100644
--- a/xarray/tests/test_formatting.py
+++ b/xarray/tests/test_formatting.py
@@ -103,6 +103,7 @@ def test_format_item(self) -> None:
             (np.float64(22.222222), "22.22"),
             (np.zeros((1, 1)), "0.0"),
             (np.zeros(2), "[0. 0.]"),
+            (np.zeros((2, 2)), "[[0. 0.]\n [0. 0.]]"),
         ]
         for item, expected in cases:
             actual = formatting.format_item(item)