workaround for PYthon 3.12 ncompress bug

This allows non-Hatanaka, non-LZW files to be read with Python 3.12

valgur/ncompress#2

src/georinex/rio.py

@@ -10,8 +10,17 @@
 
 import xarray
 
-from hatanaka import crx2rnx
-from ncompress import decompress as unlzw
+try:
+    from hatanaka import crx2rnx
+except ImportError:
+    logging.info("hatanaka crx2rnx not available")
+    crx2rnx = None
+
+try:
+    from ncompress import decompress as unlzw
+except ImportError:
+    logging.info("ncompress unlzw not available")
+    unlzw = None
 
 
 @contextmanager
@@ -77,6 +86,9 @@ def opener(fn: T.TextIO | Path, header: bool = False) -> T.Iterator[T.TextIO]:
                         )
                         yield f
         elif suffix == ".z" or magic.startswith(b"\x1f\x9d"):
+            if unlzw is None:
+                raise ImportError("ncompress unlzw not available")
+
             with fn.open("rb") as zu:
                 with io.StringIO(unlzw(zu.read()).decode("ascii")) as f:
                     _, is_crinex = rinex_version(first_nonblank_line(f))

src/georinex/tests/test_hatanaka.py

@@ -12,6 +12,8 @@
 
 
 def test_obs2():
+    pytest.importorskip("hatanaka")
+
     fn = R / "york0440.15d"
 
     info = gr.rinexinfo(fn)
@@ -29,6 +31,8 @@ def test_obs2():
 
 @pytest.mark.timeout(30)
 def test_obs3_gz():
+    pytest.importorskip("hatanaka")
+
     fn = R / "CEBR00ESP_R_20182000000_01D_30S_MO.crx.gz"
 
     info = gr.rinexinfo(fn)
@@ -90,6 +94,8 @@ def test_obs3_gz():
 @pytest.mark.timeout(30)
 @pytest.mark.parametrize("suffix", [".crx", ".crx.bz2"])
 def test_obs3_crx(suffix):
+    pytest.importorskip("hatanaka")
+
     fn = R / ("P43300USA_R_20190012056_17M_15S_MO" + suffix)
 
     info = gr.rinexinfo(fn)