Allow passing None explicitly to pygmt functions Part 1 (#1857)

Implements a more robust check for None values in pygmt functions.

* Let grdimage shading=None or False work

Refactor grdimage to check `if "I" in kwargs` to using `if kwargs.get("I") is not None`.

* Let grd2cpt's categorical, cyclic and output work with None input
* Let grd2xyz's outcols work with None input

Specifically when output_type="pandas" too.

* Let grdgradient's tiles, normalize and outgrid work with None input
* Let grdview's drapegrid work with None inputs
* Let makecpt's categorical, cyclic and output work with None inputs
* Let plot's style, color, intensity and transparency work with None input
* Let plot3d's style, color, intensity & transparency work with None input
* Let solar's T work with None input
* Let transparency work with 0, None and False input
* Let project's center, convention and generate work with None inputs
* Let velo's spec work with None inputs

Or rather, catch it properly if someone uses spec=None.

* Update pygmt/src/grdgradient.py using walrus operator

Co-authored-by: Meghan Jones <[email protected]>
Co-authored-by: Dongdong Tian <[email protected]>

Author: 3 people

pygmt/src/grd2cpt.py

@@ -160,14 +160,14 @@ def grd2cpt(grid, **kwargs):
         ``categorical=True``.
     {V}
     """
-    if "W" in kwargs and "Ww" in kwargs:
+    if kwargs.get("W") is not None and kwargs.get("Ww") is not None:
         raise GMTInvalidInput("Set only categorical or cyclic to True, not both.")
     with Session() as lib:
         file_context = lib.virtualfile_from_data(check_kind="raster", data=grid)
         with file_context as infile:
-            if "H" not in kwargs:  # if no output is set
+            if kwargs.get("H") is None:  # if no output is set
                 arg_str = build_arg_string(kwargs, infile=infile)
-            if "H" in kwargs:  # if output is set
+            else:  # if output is set
                 outfile, kwargs["H"] = kwargs["H"], True
                 if not outfile or not isinstance(outfile, str):
                     raise GMTInvalidInput("'output' should be a proper file name.")

pygmt/src/grd2xyz.py

@@ -159,7 +159,7 @@ def grd2xyz(grid, output_type="pandas", outfile=None, **kwargs):
     elif outfile is None and output_type == "file":
         raise GMTInvalidInput("Must specify 'outfile' for ASCII output.")
 
-    if "o" in kwargs and output_type == "pandas":
+    if kwargs.get("o") is not None and output_type == "pandas":
         raise GMTInvalidInput(
             "If 'outcols' is specified, 'output_type' must be either 'numpy'"
             "or 'file'."

pygmt/src/grdgradient.py

@@ -164,7 +164,7 @@ def grdgradient(grid, **kwargs):
     >>> new_grid = pygmt.grdgradient(grid=grid, azimuth=10)
     """
     with GMTTempFile(suffix=".nc") as tmpfile:
-        if "Q" in kwargs and "N" not in kwargs:
+        if kwargs.get("Q") is not None and kwargs.get("N") is None:
             raise GMTInvalidInput("""Must specify normalize if tiles is specified.""")
         if not args_in_kwargs(args=["A", "D", "E"], kwargs=kwargs):
             raise GMTInvalidInput(
@@ -174,9 +174,8 @@ def grdgradient(grid, **kwargs):
         with Session() as lib:
             file_context = lib.virtualfile_from_data(check_kind="raster", data=grid)
             with file_context as infile:
-                if "G" not in kwargs:  # if outgrid is unset, output to tempfile
-                    kwargs.update({"G": tmpfile.name})
-                outgrid = kwargs["G"]
+                if (outgrid := kwargs.get("G")) is None:
+                    kwargs["G"] = outgrid = tmpfile.name  # output to tmpfile
                 lib.call_module("grdgradient", build_arg_string(kwargs, infile=infile))
 
         return load_dataarray(outgrid) if outgrid == tmpfile.name else None

pygmt/src/grdimage.py

@@ -166,7 +166,7 @@ def grdimage(self, grid, **kwargs):
         file_context = lib.virtualfile_from_data(check_kind="raster", data=grid)
         with contextlib.ExitStack() as stack:
             # shading using an xr.DataArray
-            if "I" in kwargs and data_kind(kwargs["I"]) == "grid":
+            if kwargs.get("I") is not None and data_kind(kwargs["I"]) == "grid":
                 shading_context = lib.virtualfile_from_grid(kwargs["I"])
                 kwargs["I"] = stack.enter_context(shading_context)
 

pygmt/src/grdview.py

@@ -126,7 +126,8 @@ def grdview(self, grid, **kwargs):
         file_context = lib.virtualfile_from_data(check_kind="raster", data=grid)
 
         with contextlib.ExitStack() as stack:
-            if "G" in kwargs:  # deal with kwargs["G"] if drapegrid is xr.DataArray
+            if kwargs.get("G") is not None:
+                # deal with kwargs["G"] if drapegrid is xr.DataArray
                 drapegrid = kwargs["G"]
                 if data_kind(drapegrid) in ("file", "grid"):
                     if data_kind(drapegrid) == "grid":

pygmt/src/makecpt.py

@@ -147,11 +147,11 @@ def makecpt(**kwargs):
         ``categorical=True``.
     """
     with Session() as lib:
-        if "W" in kwargs and "Ww" in kwargs:
+        if kwargs.get("W") is not None and kwargs.get("Ww") is not None:
             raise GMTInvalidInput("Set only categorical or cyclic to True, not both.")
-        if "H" not in kwargs:  # if no output is set
+        if kwargs.get("H") is None:  # if no output is set
             arg_str = build_arg_string(kwargs)
-        elif "H" in kwargs:  # if output is set
+        else:  # if output is set
             outfile, kwargs["H"] = kwargs.pop("H"), True
             if not outfile or not isinstance(outfile, str):
                 raise GMTInvalidInput("'output' should be a proper file name.")

pygmt/src/plot.py

@@ -218,15 +218,15 @@ def plot(self, data=None, x=None, y=None, size=None, direction=None, **kwargs):
     kind = data_kind(data, x, y)
 
     extra_arrays = []
-    if "S" in kwargs and kwargs["S"][0] in "vV" and direction is not None:
+    if kwargs.get("S") is not None and kwargs["S"][0] in "vV" and direction is not None:
         extra_arrays.extend(direction)
     elif (
-        "S" not in kwargs
+        kwargs.get("S") is None
         and kind == "geojson"
         and data.geom_type.isin(["Point", "MultiPoint"]).all()
     ):  # checking if the geometry of a geoDataFrame is Point or MultiPoint
         kwargs["S"] = "s0.2c"
-    elif "S" not in kwargs and kind == "file" and data.endswith(".gmt"):
+    elif kwargs.get("S") is None and kind == "file" and data.endswith(".gmt"):
         # checking that the data is a file path to set default style
         try:
             with open(which(data), mode="r", encoding="utf8") as file:
@@ -236,7 +236,7 @@ def plot(self, data=None, x=None, y=None, size=None, direction=None, **kwargs):
                 kwargs["S"] = "s0.2c"
         except FileNotFoundError:
             pass
-    if "G" in kwargs and is_nonstr_iter(kwargs["G"]):
+    if kwargs.get("G") is not None and is_nonstr_iter(kwargs["G"]):
         if kind != "vectors":
             raise GMTInvalidInput(
                 "Can't use arrays for color if data is matrix or file."
@@ -251,7 +251,7 @@ def plot(self, data=None, x=None, y=None, size=None, direction=None, **kwargs):
         extra_arrays.append(size)
 
     for flag in ["I", "t"]:
-        if flag in kwargs and is_nonstr_iter(kwargs[flag]):
+        if kwargs.get(flag) is not None and is_nonstr_iter(kwargs[flag]):
             if kind != "vectors":
                 raise GMTInvalidInput(
                     f"Can't use arrays for {plot.aliases[flag]} if data is matrix or file."

pygmt/src/plot3d.py

@@ -188,15 +188,15 @@ def plot3d(
     kind = data_kind(data, x, y, z)
 
     extra_arrays = []
-    if "S" in kwargs and kwargs["S"][0] in "vV" and direction is not None:
+    if kwargs.get("S") is not None and kwargs["S"][0] in "vV" and direction is not None:
         extra_arrays.extend(direction)
     elif (
-        "S" not in kwargs
+        kwargs.get("S") is None
         and kind == "geojson"
         and data.geom_type.isin(["Point", "MultiPoint"]).all()
     ):  # checking if the geometry of a geoDataFrame is Point or MultiPoint
         kwargs["S"] = "u0.2c"
-    elif "S" not in kwargs and kind == "file" and data.endswith(".gmt"):
+    elif kwargs.get("S") is None and kind == "file" and data.endswith(".gmt"):
         # checking that the data is a file path to set default style
         try:
             with open(which(data), mode="r", encoding="utf8") as file:
@@ -206,7 +206,7 @@ def plot3d(
                 kwargs["S"] = "u0.2c"
         except FileNotFoundError:
             pass
-    if "G" in kwargs and is_nonstr_iter(kwargs["G"]):
+    if kwargs.get("G") is not None and is_nonstr_iter(kwargs["G"]):
         if kind != "vectors":
             raise GMTInvalidInput(
                 "Can't use arrays for color if data is matrix or file."
@@ -221,7 +221,7 @@ def plot3d(
         extra_arrays.append(size)
 
     for flag in ["I", "t"]:
-        if flag in kwargs and is_nonstr_iter(kwargs[flag]):
+        if kwargs.get(flag) is not None and is_nonstr_iter(kwargs[flag]):
             if kind != "vectors":
                 raise GMTInvalidInput(
                     f"Can't use arrays for {plot3d.aliases[flag]} if data is matrix or file."

pygmt/src/project.py

@@ -210,13 +210,13 @@ def project(data=None, x=None, y=None, z=None, outfile=None, **kwargs):
           by ``outfile``)
     """
 
-    if "C" not in kwargs:
+    if kwargs.get("C") is None:
         raise GMTInvalidInput("The `center` parameter must be specified.")
-    if "G" not in kwargs and data is None:
+    if kwargs.get("G") is None and data is None:
         raise GMTInvalidInput(
             "The `data` parameter must be specified unless `generate` is used."
         )
-    if "G" in kwargs and "F" in kwargs:
+    if kwargs.get("G") is not None and kwargs.get("F") is not None:
         raise GMTInvalidInput(
             "The `convention` parameter is not allowed with `generate`."
         )
@@ -225,7 +225,7 @@ def project(data=None, x=None, y=None, z=None, outfile=None, **kwargs):
         if outfile is None:  # Output to tmpfile if outfile is not set
             outfile = tmpfile.name
         with Session() as lib:
-            if "G" not in kwargs:
+            if kwargs.get("G") is None:
                 # Choose how data will be passed into the module
                 table_context = lib.virtualfile_from_data(
                     check_kind="vector", data=data, x=x, y=y, z=z, required_z=False
@@ -240,7 +240,7 @@ def project(data=None, x=None, y=None, z=None, outfile=None, **kwargs):
 
         # if user did not set outfile, return pd.DataFrame
         if outfile == tmpfile.name:
-            if "G" in kwargs:
+            if kwargs.get("G") is not None:
                 column_names = list("rsp")
                 result = pd.read_csv(tmpfile.name, sep="\t", names=column_names)
             else:

pygmt/src/solar.py

@@ -66,7 +66,7 @@ def solar(self, terminator="d", terminator_datetime=None, **kwargs):
     """
 
     kwargs = self._preprocess(**kwargs)  # pylint: disable=protected-access
-    if "T" in kwargs:
+    if kwargs.get("T") is not None:
         raise GMTInvalidInput(
             "Use 'terminator' and 'terminator_datetime' instead of 'T'."
         )