TYP: Add return type hints for functions that return None

pygmt/_show_versions.py

@@ -85,7 +85,7 @@ def _check_ghostscript_version(gs_version: str | None) -> str | None:
     return None
 
 
-def show_versions(file: TextIO | None = sys.stdout):
+def show_versions(file: TextIO | None = sys.stdout) -> None:
     """
     Print various dependency versions which are useful when submitting bug reports.
 

pygmt/clib/session.py

@@ -327,7 +327,7 @@ def get_libgmt_func(
             function.restype = restype
         return function
 
-    def create(self, name: str):
+    def create(self, name: str) -> None:
         """
         Create a new GMT C API session.
 
@@ -594,7 +594,7 @@ def get_common(self, option: str) -> bool | int | float | np.ndarray:
             case _:  # 'status' is the option value (in integer type).
                 return status
 
-    def call_module(self, module: str, args: str | list[str]):
+    def call_module(self, module: str, args: str | list[str]) -> None:
         """
         Call a GMT module with the given arguments.
 
@@ -946,7 +946,9 @@ def _check_dtype_and_dim(self, array: np.ndarray, ndim: int) -> int:
             raise GMTInvalidInput(msg)
         return self[DTYPES[dtype]]
 
-    def put_vector(self, dataset: ctp.c_void_p, column: int, vector: np.ndarray):
+    def put_vector(
+        self, dataset: ctp.c_void_p, column: int, vector: np.ndarray
+    ) -> None:
         r"""
         Attach a 1-D numpy array as a column on a GMT dataset.
 
@@ -1005,7 +1007,9 @@ def put_vector(self, dataset: ctp.c_void_p, column: int, vector: np.ndarray):
             )
             raise GMTCLibError(msg)
 
-    def put_strings(self, dataset: ctp.c_void_p, family: str, strings: np.ndarray):
+    def put_strings(
+        self, dataset: ctp.c_void_p, family: str, strings: np.ndarray
+    ) -> None:
         """
         Attach a 1-D numpy array of dtype str as a column on a GMT dataset.
 
@@ -1059,7 +1063,9 @@ def put_strings(self, dataset: ctp.c_void_p, family: str, strings: np.ndarray):
             msg = f"Failed to put strings of type {strings.dtype} into dataset."
             raise GMTCLibError(msg)
 
-    def put_matrix(self, dataset: ctp.c_void_p, matrix: np.ndarray, pad: int = 0):
+    def put_matrix(
+        self, dataset: ctp.c_void_p, matrix: np.ndarray, pad: int = 0
+    ) -> None:
         """
         Attach a 2-D numpy array to a GMT dataset.
 
@@ -1204,7 +1210,7 @@ def read_data(
             raise GMTCLibError(msg)
         return ctp.cast(data_ptr, ctp.POINTER(dtype))
 
-    def write_data(self, family, geometry, mode, wesn, output, data):
+    def write_data(self, family, geometry, mode, wesn, output, data) -> None:
         """
         Write a GMT data container to a file.
 

pygmt/figure.py

@@ -95,19 +95,19 @@ class Figure:
     122.94, 145.82, 20.53, 45.52
     """
 
-    def __init__(self):
+    def __init__(self) -> None:
         self._name = unique_name()
         self._preview_dir = TemporaryDirectory(prefix=f"{self._name}-preview-")
         self._activate_figure()
 
-    def __del__(self):
+    def __del__(self) -> None:
         """
         Clean up the temporary directory that stores the previews.
         """
         if hasattr(self, "_preview_dir"):
             self._preview_dir.cleanup()
 
-    def _activate_figure(self):
+    def _activate_figure(self) -> None:
         """
         Start and/or activate the current figure.
 
@@ -144,7 +144,7 @@ def savefig(
         show: bool = False,
         worldfile: bool = False,
         **kwargs,
-    ):
+    ) -> None:
         """
         Save the figure to an image file.
 
@@ -268,7 +268,7 @@ def show(
         width: int = 500,
         waiting: float = 0.5,
         **kwargs,
-    ):
+    ) -> None:
         """
         Display a preview of the figure.
 
@@ -442,7 +442,7 @@ def _repr_html_(self) -> str:
     )
 
 
-def set_display(method: Literal["external", "notebook", "none", None] = None):
+def set_display(method: Literal["external", "notebook", "none", None] = None) -> None:
     """
     Set the display method when calling :meth:`pygmt.Figure.show`.
 

pygmt/helpers/caching.py

@@ -5,7 +5,7 @@
 from pygmt.src import which
 
 
-def cache_data():
+def cache_data() -> None:
     """
     Download GMT remote data files used in PyGMT tests and docs to cache folder.
     """

pygmt/helpers/tempfile.py

@@ -59,7 +59,7 @@ class GMTTempFile:
     [0. 0. 0.] [1. 1. 1.] [2. 2. 2.]
     """
 
-    def __init__(self, prefix: str = "pygmt-", suffix: str = ".txt"):
+    def __init__(self, prefix: str = "pygmt-", suffix: str = ".txt") -> None:
         """
         Initialize the object.
         """

pygmt/helpers/utils.py

@@ -43,7 +43,7 @@
 
 def _validate_data_input(
     data=None, x=None, y=None, z=None, required_z=False, required_data=True, kind=None
-):
+) -> None:
     """
     Check if the combination of data/x/y/z is valid.
 
@@ -552,7 +552,7 @@ def is_nonstr_iter(value):
     return isinstance(value, Iterable) and not isinstance(value, str)
 
 
-def launch_external_viewer(fname: str, waiting: float = 0):
+def launch_external_viewer(fname: str, waiting: float = 0) -> None:
     """
     Open a file in an external viewer program.
 

pygmt/session_management.py

@@ -9,7 +9,7 @@
 from pygmt.helpers import unique_name
 
 
-def begin():
+def begin() -> None:
     """
     Initiate a new GMT modern mode session.
 
@@ -28,7 +28,7 @@ def begin():
         lib.call_module(module="set", args=["GMT_COMPATIBILITY=6"])
 
 
-def end():
+def end() -> None:
     """
     Terminate the GMT modern mode session created by :func:`pygmt.begin`.