Python 3.8 walrus if :=

scripts/plot_all_subdir.py

@@ -63,9 +63,7 @@ def main(top: Path, resume: bool) -> None:
     )
     P = p.parse_args()
 
-    top_dir = Path(P.top_dir).expanduser()
-
-    if not top_dir.is_dir():
+    if not (top_dir := Path(P.top_dir).expanduser()).is_dir():
         raise NotADirectoryError(top_dir)
 
     main(top_dir, P.resume)

scripts/plot_look_all.py

@@ -24,12 +24,9 @@
 p.add_argument("new_dir", help="New: top level directory to look one level below")
 P = p.parse_args()
 
-ref_dir = Path(P.ref_dir).expanduser().resolve()
-new_dir = Path(P.new_dir).expanduser().resolve()
-
-if not ref_dir.is_dir():
+if not (ref_dir := Path(P.ref_dir).expanduser().resolve()).is_dir():
     raise NotADirectoryError(ref_dir)
-if not new_dir.is_dir():
+if not (new_dir := Path(P.new_dir).expanduser().resolve()).is_dir():
     raise NotADirectoryError(new_dir)
 if ref_dir.samefile(new_dir):
     raise ValueError("ref_dir and new_dir must be different")
@@ -48,11 +45,9 @@
 
     for v in var:
         plot_name = sorted((new_sim / "plots").glob(f"{v}-*.png"))[-1].name
-        ref_file = ref_dir / new_name / "plots" / plot_name
-        new_file = new_sim / "plots" / plot_name
-
-        if not ref_file.is_file():
+        if not (ref_file := ref_dir / new_name / "plots" / plot_name).is_file():
             raise FileNotFoundError(ref_file)
+        new_file = new_sim / "plots" / plot_name
 
         axs[0].imshow(imread(ref_file))
         axs[0].set_title(ref_file, fontsize=fs)

scripts/plot_patch.py

@@ -31,8 +31,7 @@
 if args.verbose:
     logging.basicConfig(level=logging.DEBUG)
 
-indir = Path(args.indir).expanduser()
-if not indir.is_dir():
+if not (indir := Path(args.indir).expanduser()).is_dir():
     raise NotADirectoryError(indir)
 
 plot.patch(indir, var=set(args.var))

src/gemini3d/archive.py

@@ -6,14 +6,12 @@
 
 
 def cmake_exe() -> str:
-    cmake = shutil.which("cmake")
-    if not cmake:
+    if not (cmake := shutil.which("cmake")):
         # try to help if Homebrew or Ports is not on PATH
         if sys.platform == "darwin":
             paths = ["/opt/homebrew/bin", "/usr/local/bin", "/opt/local/bin"]
             for path in paths:
-                cmake = shutil.which("cmake", path=path)
-                if cmake:
+                if cmake := shutil.which("cmake", path=path):
                     break
 
     if not cmake:
@@ -47,8 +45,7 @@ def extract(archive: str | Path, out_path: str | Path):
       directory to extract files and directories to
     """
 
-    archive = Path(archive).expanduser().resolve()
-    if not archive.is_file():
+    if not (archive := Path(archive).expanduser().resolve()).is_file():
         raise FileNotFoundError(archive)
 
     out_path = Path(out_path).expanduser().resolve()

src/gemini3d/compare/out.py

@@ -36,8 +36,7 @@ def compare_output(
 
     for i, t in enumerate(params["time"]):
         st = f"UTsec {t}"
-        A = read.frame(new_dir, t)
-        if not A:
+        if not (A := read.frame(new_dir, t)):
             raise FileNotFoundError(f"{new_dir} does not appear to contain data at {t}")
         B = read.frame(ref_dir, t)
 

src/gemini3d/find.py

@@ -49,8 +49,7 @@ def executable(name: str, root: Path | None = None) -> Path:
     if not name:
         raise ValueError("executable name must be non-empty")
 
-    ep = Path(name).expanduser()
-    if ep.is_file():
+    if (ep := Path(name).expanduser()).is_file():
         return ep
 
     exe_paths = EXE_PATHS
@@ -133,8 +132,7 @@ def frame(simdir: Path, time: datetime) -> Path:
         + f"{time.microsecond:06d}"
     )
 
-    fn = simdir / (stem + suffix)
-    if fn.is_file():
+    if (fn := simdir / (stem + suffix)).is_file():
         return fn
 
     # %% WORKAROUND for real32 file ticks. This will be removed when datetime-fortran is implemented
@@ -171,19 +169,14 @@ def grid(path: Path) -> Path:
 def find_stem(path: Path, stem: str, suffix: str = ".h5") -> Path | None:
     """find file containing stem"""
 
-    path = Path(path).expanduser()
-
-    if path.is_file():
+    if (path := Path(path).expanduser()).is_file():
         if stem in path.stem:
             return path
-        else:
-            found = find_stem(path.parent, stem, path.suffix)
-            if found:
-                return found
+        elif found := find_stem(path.parent, stem, path.suffix):
+            return found
     elif path.is_dir():
         for p in (path, path / "inputs"):
-            f = p / (stem + suffix)
-            if f.is_file():
+            if (f := p / (stem + suffix)).is_file():
                 return f
 
     return None

src/gemini3d/job.py

@@ -60,14 +60,12 @@ def runner(pr: dict[str, typing.Any]) -> None:
 
     # %% setup Efield if needed
     if "E0dir" in p:
-        E0dir = out_dir / p["E0dir"]
-        if not E0dir.is_dir():
+        if not (out_dir / p["E0dir"]).is_dir():
             model.setup(p["nml"], out_dir)
 
     # %% setup precip if needed
     if "precdir" in p:
-        precdir = out_dir / p["precdir"]
-        if not precdir.is_dir():
+        if not (out_dir / p["precdir"]).is_dir():
             model.setup(p["nml"], out_dir)
 
     # build checks
@@ -164,9 +162,10 @@ def memory_estimate(path: Path) -> int:
 
 def check_compiler():
     fc = os.environ.get("FC")
-    fc = shutil.which(fc) if fc else shutil.which("gfortran")
-    if not fc:
-        raise EnvironmentError("Cannot find Fortran compiler e.g. Gfortran")
+    if fc := shutil.which(fc if fc else "gfortran"):
+        return fc
+
+    raise EnvironmentError("Cannot find Fortran compiler e.g. Gfortran")
 
 
 def check_mpiexec(mpiexec_name: str, gemexe: Path) -> str:
@@ -178,12 +177,10 @@ def check_mpiexec(mpiexec_name: str, gemexe: Path) -> str:
     if not mpiexec_name:
         mpiexec_name = "mpiexec"
 
-    mpi_root = os.environ.get("MPI_ROOT", None)
-    if mpi_root:
+    if mpi_root := os.environ.get("MPI_ROOT", None):
         mpi_root += "/bin"
 
-    mpiexec = shutil.which(mpiexec_name, path=mpi_root)
-    if not mpiexec:
+    if not (mpiexec := shutil.which(mpiexec_name, path=mpi_root)):
         raise FileNotFoundError(f"Cannot find mpiexec {mpiexec_name}")
 
     ret = subprocess.run([mpiexec, "-help"], capture_output=True, text=True, timeout=5)
@@ -210,8 +207,7 @@ def check_mpiexec(mpiexec_name: str, gemexe: Path) -> str:
 
 
 def check_outdir(out_dir: str | Path) -> Path:
-    out_dir = Path(out_dir).expanduser().resolve()
-    if out_dir.is_file():
+    if (out_dir := Path(out_dir).expanduser().resolve()).is_file():
         raise NotADirectoryError(
             f"please specify output DIRECTORY, you specified {out_dir}"
         )

src/gemini3d/linux_info.py

@@ -22,8 +22,7 @@ def os_release() -> list[str]:
     if sys.platform != "linux":
         return []
 
-    fn = Path("/etc/os-release")
-    if not fn.is_file():
+    if not (fn := Path("/etc/os-release")).is_file():
         if Path("/etc/redhat-release").is_file() or Path("/etc/centos-release").is_file():
             return ["rhel"]
         elif Path("/etc/debian_version").is_file():

src/gemini3d/namelist.py

@@ -101,9 +101,7 @@ def _write_value(f, key: str, value: T.Any):
         else:
             raise TypeError(f"unsure how to handle {type(value)}")
 
-    file = file.expanduser().resolve()
-
-    if file.is_dir():
+    if (file := file.expanduser().resolve()).is_dir():
         raise OSError(f"give a filename, not a directory {file}")
 
     mode = "w" if overwrite else "a"

src/gemini3d/patch/__init__.py

@@ -23,8 +23,7 @@ def filenames2times(indir: Path) -> list[datetime]:
     get times from filenames
     """
 
-    indir = Path(indir).expanduser()
-    if not indir.is_dir():
+    if not (indir := Path(indir).expanduser()).is_dir():
         raise NotADirectoryError(indir)
 
     times = []

src/gemini3d/read.py

@@ -109,8 +109,7 @@ def frame(
     var = set(var)
 
     # %% file or directory
-    path = Path(path).expanduser()
-    if path.is_dir():
+    if (path := Path(path).expanduser()).is_dir():
         if time is None:
             raise ValueError(
                 f"must specify time when giving directory {path} instead of file"

src/gemini3d/tests/intg/test_grid_matlab.py

@@ -25,19 +25,16 @@ def test_tilted_dipole():
         pytest.skip("Matlab engine not available")
 
     # find MatGemini
-    root = os.environ.get("MATGEMINI")
-    if not root:
+    if not (root := os.environ.get("MATGEMINI")):
         # guess
         root = Path(__file__).parents[5] / "mat_gemini"
 
-    root = Path(root).expanduser()
-    if not root.is_dir():
+    if not (root := Path(root).expanduser()).is_dir():
         raise FileNotFoundError(
             "Please set MATGEMINI environment variable with top-level mat_gemini directory."
             f"\nMatGemini not found at {root}"
         )
-    mg_setup = root / "setup.m"
-    if not mg_setup.is_file():
+    if not (mg_setup := root / "setup.m").is_file():
         raise FileNotFoundError(str(mg_setup))
 
     eng = mateng.start_matlab("-nojvm")

src/gemini3d/tests/intg/test_model.py

@@ -48,8 +48,7 @@ def test_model_setup(name, tmp_path, monkeypatch, helpers):
 
     # patch eq_dir to use reference data
     if "eq_dir" in params:
-        eq_dir = test_dir.parent / params["eq_dir"].name
-        if eq_dir.is_dir():
+        if (eq_dir := test_dir.parent / params["eq_dir"].name).is_dir():
             print(f"Using {eq_dir} for equilibrium data")
         params["eq_dir"] = eq_dir
 

src/gemini3d/utils.py

@@ -53,14 +53,11 @@ def str2func(name: str, path: Path | None = None) -> T.Callable:
             mod = importlib.import_module(func_name)
         else:
             # https://docs.python.org/3.10/library/importlib.html#importing-a-source-file-directly
-            mod_file = path / (name + ".py")
-            if not mod_file.is_file():
+            if not (mod_file := path / (name + ".py")).is_file():
                 raise FileNotFoundError(mod_file)
-            spec = importlib.util.spec_from_file_location(name, mod_file)
-            if spec is None:
+            if (spec := importlib.util.spec_from_file_location(name, mod_file)) is None:
                 raise ModuleNotFoundError(f"{name} not found in {mod_file}")
-            mod = importlib.util.module_from_spec(spec)
-            if mod is None:
+            if (mod := importlib.util.module_from_spec(spec)) is None:
                 raise ImportError(f"could not import {name} from {mod_file}")
             spec.loader.exec_module(mod)  # type: ignore
 

src/gemini3d/web.py

@@ -18,9 +18,7 @@ def git_download(path: Path, repo: str, tag: str | None = None):
     Use Git to download code repo.
     """
 
-    git = shutil.which("git")
-
-    if not git:
+    if not (git := shutil.which("git")):
         raise FileNotFoundError("Git not found.")
 
     if not tag:
@@ -48,9 +46,8 @@ def git_download(path: Path, repo: str, tag: str | None = None):
 
 
 def download_and_extract(test_name: str, data_dir: Path) -> Path:
-    ref_file = data_dir / "ref_data.json"
 
-    if not ref_file.is_file():
+    if not (ref_file := data_dir / "ref_data.json").is_file():
         jmeta = json.loads(
             (importlib.resources.files("gemini3d") / "libraries.json").read_text()
         )

src/gemini3d/write.py

@@ -52,8 +52,7 @@ def grid(cfg: dict[str, T.Any], xg: dict[str, T.Any]) -> None:
         grid values
     """
 
-    input_dir = cfg["indat_size"].parent
-    if input_dir.is_file():
+    if (input_dir := cfg["indat_size"].parent).is_file():
         raise OSError(f"{input_dir} is a file instead of directory")
 
     input_dir.mkdir(parents=True, exist_ok=True)
@@ -129,8 +128,7 @@ def meta(fn: Path, git_meta: dict[str, str], cfg: dict[str, T.Any]) -> None:
     if "eq_dir" in cfg:
         # JSON does not allow unescaped backslash
         jm["equilibrium"] = {"eq_dir": cfg["eq_dir"].as_posix()}
-        hf = cfg["eq_dir"] / "sha256sum.txt"
-        if hf.is_file():
+        if (hf := cfg["eq_dir"] / "sha256sum.txt").is_file():
             jm["equilibrium"]["sha256"] = hf.read_text().strip()
 
     js = json.dumps(jm, sort_keys=True, indent=2)