pyarrow: Check compatibility of pyarrow.array with string type (#2933)

Co-authored-by: Dongdong Tian <seisman.info@gmail.com>

Author: weiji14

doc/conf.py

@@ -85,6 +85,7 @@
     "contextily": ("https://contextily.readthedocs.io/en/stable/", None),
     "geopandas": ("https://geopandas.org/en/stable/", None),
     "numpy": ("https://numpy.org/doc/stable/", None),
+    "pyarrow": ("https://arrow.apache.org/docs/", None),
     "python": ("https://docs.python.org/3/", None),
     "pandas": ("https://pandas.pydata.org/pandas-docs/stable/", None),
     "rasterio": ("https://rasterio.readthedocs.io/en/stable/", None),

doc/ecosystem.md

@@ -94,9 +94,9 @@ Python objects. They are based on the C++ implementation of Arrow.
 ```{note}
 If you have [PyArrow][] installed, PyGMT does have some initial support for
 `pandas.Series` and `pandas.DataFrame` objects with Apache Arrow-backed arrays.
-Specifically, only uint/int/float and date32/date64 are supported for now.
-Support for string Array dtypes, Duration types and GeoArrow geometry types is still a work in progress.
-For more details, see
+Specifically, only uint/int/float, date32/date64 and string types are supported for now.
+Support for Duration types and GeoArrow geometry types is still a work in progress. For
+more details, see
 [issue #2800](https://github.com/GenericMappingTools/pygmt/issues/2800).
 ```
 

pygmt/_typing.py

@@ -2,7 +2,17 @@
 Type aliases for type hints.
 """
 
+import contextlib
+import importlib
+from collections.abc import Sequence
 from typing import Literal
 
+import numpy as np
+
 # Anchor codes
 AnchorCode = Literal["TL", "TC", "TR", "ML", "MC", "MR", "BL", "BC", "BR"]
+
+# String array types
+StringArrayTypes = Sequence[str] | np.ndarray
+with contextlib.suppress(ImportError):
+    StringArrayTypes |= importlib.import_module(name="pyarrow").StringArray

pygmt/clib/conversion.py

@@ -280,12 +280,13 @@ def sequence_to_ctypes_array(
 
 def strings_to_ctypes_array(strings: Sequence[str] | np.ndarray) -> ctp.Array:
     """
-    Convert a sequence (e.g., a list) of strings into a ctypes array.
+    Convert a sequence (e.g., a list) of strings or numpy.ndarray of strings into a
+    ctypes array.
 
     Parameters
     ----------
     strings
-        A sequence of strings.
+        A sequence of strings, or a numpy.ndarray of str dtype.
 
     Returns
     -------

pygmt/src/text.py

@@ -5,7 +5,7 @@
 from collections.abc import Sequence
 
 import numpy as np
-from pygmt._typing import AnchorCode
+from pygmt._typing import AnchorCode, StringArrayTypes
 from pygmt.clib import Session
 from pygmt.exceptions import GMTInvalidInput
 from pygmt.helpers import (
@@ -48,7 +48,7 @@ def text_(  # noqa: PLR0912
     x=None,
     y=None,
     position: AnchorCode | None = None,
-    text=None,
+    text: str | StringArrayTypes | None = None,
     angle=None,
     font=None,
     justify: bool | None | AnchorCode | Sequence[AnchorCode] = None,
@@ -104,7 +104,7 @@ def text_(  # noqa: PLR0912
 
         For example, ``position="TL"`` plots the text at the Top Left corner
         of the map.
-    text : str or 1-D array
+    text
         The text string, or an array of strings to plot on the figure.
     angle: float, str, bool or list
         Set the angle measured in degrees counter-clockwise from

pygmt/tests/test_clib_virtualfile_from_vectors.py

@@ -11,6 +11,14 @@
 from pygmt.clib.session import DTYPES_NUMERIC
 from pygmt.exceptions import GMTInvalidInput
 from pygmt.helpers import GMTTempFile
+from pygmt.helpers.testing import skip_if_no
+
+try:
+    import pyarrow as pa
+
+    pa_array = pa.array
+except ImportError:
+    pa_array = None
 
 
 @pytest.fixture(scope="module", name="dtypes")
@@ -53,17 +61,30 @@ def test_virtualfile_from_vectors(dtypes):
 
 
 @pytest.mark.benchmark
-@pytest.mark.parametrize("dtype", [str, object])
-def test_virtualfile_from_vectors_one_string_or_object_column(dtype):
-    """
-    Test passing in one column with string or object dtype into virtual file dataset.
+@pytest.mark.parametrize(
+    ("array_func", "dtype"),
+    [
+        pytest.param(np.array, {"dtype": np.str_}, id="str"),
+        pytest.param(np.array, {"dtype": np.object_}, id="object"),
+        pytest.param(
+            pa_array,
+            {},  # {"type": pa.string()}
+            marks=skip_if_no(package="pyarrow"),
+            id="pyarrow",
+        ),
+    ],
+)
+def test_virtualfile_from_vectors_one_string_or_object_column(array_func, dtype):
+    """
+    Test passing in one column with string (numpy/pyarrow) or object (numpy)
+    dtype into virtual file dataset.
     """
     size = 5
     x = np.arange(size, dtype=np.int32)
     y = np.arange(size, size * 2, 1, dtype=np.int32)
-    strings = np.array(["a", "bc", "defg", "hijklmn", "opqrst"], dtype=dtype)
+    strings = array_func(["a", "bc", "defg", "hijklmn", "opqrst"], **dtype)
     with clib.Session() as lib:
-        with lib.virtualfile_from_vectors((x, y, strings)) as vfile:
+        with lib.virtualfile_from_vectors(vectors=(x, y, strings)) as vfile:
             with GMTTempFile() as outfile:
                 lib.call_module("convert", [vfile, f"->{outfile.name}"])
                 output = outfile.read(keep_tabs=True)

pygmt/tests/test_text.py

@@ -9,6 +9,14 @@
 from pygmt import Figure
 from pygmt.exceptions import GMTCLibError, GMTInvalidInput
 from pygmt.helpers import GMTTempFile
+from pygmt.helpers.testing import skip_if_no
+
+try:
+    import pyarrow as pa
+
+    pa_array = pa.array
+except ImportError:
+    pa_array = None
 
 TEST_DATA_DIR = Path(__file__).parent / "data"
 POINTS_DATA = TEST_DATA_DIR / "points.txt"
@@ -48,8 +56,16 @@ def test_text_single_line_of_text(region, projection):
 
 
 @pytest.mark.benchmark
-@pytest.mark.mpl_image_compare
-def test_text_multiple_lines_of_text(region, projection):
+@pytest.mark.mpl_image_compare(filename="test_text_multiple_lines_of_text.png")
+@pytest.mark.parametrize(
+    "array_func",
+    [
+        list,
+        pytest.param(np.array, id="numpy"),
+        pytest.param(pa_array, marks=skip_if_no(package="pyarrow"), id="pyarrow"),
+    ],
+)
+def test_text_multiple_lines_of_text(region, projection, array_func):
     """
     Place multiple lines of text at their respective x, y locations.
     """
@@ -59,7 +75,7 @@ def test_text_multiple_lines_of_text(region, projection):
         projection=projection,
         x=[1.2, 1.6],
         y=[0.6, 0.3],
-        text=["This is a line of text", "This is another line of text"],
+        text=array_func(["This is a line of text", "This is another line of text"]),
     )
     return fig