Add doctests

Author: seisman

pygmt/datatypes/header.py

@@ -70,6 +70,52 @@ class _GMT_GRID_HEADER(ctp.Structure):  # noqa: N801
 
     The class is used in the `GMT_GRID`/`GMT_IMAGE`/`GMT_CUBE` data structure. See the
     GMT source code gmt_resources.h for the original C structure definitions.
+
+    Examples
+    --------
+    >>> from pprint import pprint
+    >>> from pygmt.clib import Session
+
+    >>> with Session() as lib:
+    ...     with lib.virtualfile_out(kind="grid") as voutgrd:
+    ...         lib.call_module("read", f"@static_earth_relief.nc {voutgrd} -Tg")
+    ...         # Read the grid from the virtual file
+    ...         grid = lib.read_virtualfile(voutgrd, kind="grid")
+    ...         header = grid.contents.header.contents
+    ...         name = header.get_name()
+    ...         attrs = header.get_data_attrs()
+    ...         dims = header.get_dims()
+    ...         dim_attrs = header.get_dim_attrs()
+    ...         gtype = header.get_gtype()
+    ...         registration = header.get_registration()
+    >>> name
+    'z'
+    >>> pprint(attrs)
+    {'Conventions': 'CF-1.7',
+     'actual_range': array([190., 981.]),
+     'description': 'Reduced by Gaussian Cartesian filtering (111.2 km fullwidth) '
+                    'from SRTM15_V2.3.nc [Sandwell et al., 2022; '
+                    'https://doi.org/10.1029/2021EA002069]',
+     'history': 'grdcut @earth_relief_01d_p -R-55/-47/-24/-10 '
+                '-Gstatic_earth_relief.nc',
+     'long_name': 'elevation (m)',
+     'title': 'Produced by grdcut'}
+    >>> dims
+    ['lat', 'lon']
+    >>> pprint(dim_attrs[0])
+    {'actual_range': array([-24., -10.]),
+     'axis': 'Y',
+     'long_name': 'latitude',
+     'standard_name': 'latitude',
+     'units': 'degrees_north'}
+    >>> pprint(dim_attrs[1])
+    {'actual_range': array([-55., -47.]),
+     'axis': 'X',
+     'long_name': 'longitude',
+     'standard_name': 'longitude',
+     'units': 'degrees_east'}
+    >>> gtype, registration
+    (1, 1)
     """
 
     _fields_: ClassVar = [
@@ -212,9 +258,9 @@ def get_data_attrs(self) -> dict:
         """
         attrs: dict[str, Any] = {}
         attrs["Conventions"] = "CF-1.7"
-        attrs["title"] = self.title
-        attrs["history"] = self.command
-        attrs["description"] = self.remark
+        attrs["title"] = self.title.decode()
+        attrs["history"] = self.command.decode()
+        attrs["description"] = self.remark.decode()
         long_name, units = _parse_nameunits(self.z_units.decode())
         if long_name:
             attrs["long_name"] = long_name