From bbb14a5d8383520f1a1e7e6d885c03ecddfbcf47 Mon Sep 17 00:00:00 2001
From: Fabien Maussion
Date: Mon, 9 May 2022 17:25:01 +0200
Subject: [PATCH] Allow string formatting of scalar DataArrays (#5981)
* Allow string formatting of scalar DataArrays
* better comments
* [pre-commit.ci] auto fixes from pre-commit.com hooks
for more information, see https://pre-commit.ci
* forgot type check
* yeah, typing is new to me
* Simpler: pass to numpy in all cases
* Add dask test
* [pre-commit.ci] auto fixes from pre-commit.com hooks
for more information, see https://pre-commit.ci
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
---
xarray/core/common.py | 4 ++++
xarray/tests/test_formatting.py | 22 +++++++++++++++++++++-
2 files changed, 25 insertions(+), 1 deletion(-)
diff --git a/xarray/core/common.py b/xarray/core/common.py
index 3db9b1cfa0c..cf02bcff77b 100644
--- a/xarray/core/common.py
+++ b/xarray/core/common.py
@@ -158,6 +158,10 @@ def _repr_html_(self):
return f"{escape(repr(self))}"
return formatting_html.array_repr(self)
+ def __format__(self: Any, format_spec: str) -> str:
+ # we use numpy: scalars will print fine and arrays will raise
+ return self.values.__format__(format_spec)
+
def _iter(self: Any) -> Iterator[Any]:
for n in range(len(self)):
yield self[n]
diff --git a/xarray/tests/test_formatting.py b/xarray/tests/test_formatting.py
index 4bbf41c7b38..a5c044d8ea7 100644
--- a/xarray/tests/test_formatting.py
+++ b/xarray/tests/test_formatting.py
@@ -9,7 +9,7 @@
import xarray as xr
from xarray.core import formatting
-from . import requires_netCDF4
+from . import requires_dask, requires_netCDF4
class TestFormatting:
@@ -418,6 +418,26 @@ def test_array_repr_variable(self) -> None:
with xr.set_options(display_expand_data=False):
formatting.array_repr(var)
+ @requires_dask
+ def test_array_scalar_format(self) -> None:
+ var = xr.DataArray(0)
+ assert var.__format__("") == "0"
+ assert var.__format__("d") == "0"
+ assert var.__format__(".2f") == "0.00"
+
+ var = xr.DataArray([0.1, 0.2])
+ assert var.__format__("") == "[0.1 0.2]"
+ with pytest.raises(TypeError) as excinfo:
+ var.__format__(".2f")
+ assert "unsupported format string passed to" in str(excinfo.value)
+
+ # also check for dask
+ var = var.chunk(chunks={"dim_0": 1})
+ assert var.__format__("") == "[0.1 0.2]"
+ with pytest.raises(TypeError) as excinfo:
+ var.__format__(".2f")
+ assert "unsupported format string passed to" in str(excinfo.value)
+
def test_inline_variable_array_repr_custom_repr() -> None:
class CustomArray: