Make pyds9 an extra

pyproject.toml

@@ -30,10 +30,10 @@ lvmtools = 'lvmopstools.__main__:lvmopstools'
 [tool.poetry.dependencies]
 python = "^3.10,<3.13"
 sdsstools = "^1.3.1"
-pyds9 = "^1.8.1"
 sdss-clu = "^2.2.2"
 astropy = "^6.0.0"
 click = "^8.1.7"
+pyds9 = {version = "^1.8.1", optional = true}
 
 [tool.poetry.group.dev.dependencies]
 ipython = ">=8.0.0"
@@ -56,6 +56,9 @@ sphinx-autobuild = ">=2021.3.14"
 sphinx-autodoc-typehints = "^1.23.2"
 ruff = ">=0.1.0"
 
+[tool.poetry.extras]
+ds9 = ["pyds9"]
+
 [tool.black]
 line-length = 88
 target-version = ['py312']

src/lvmopstools/ds9.py

@@ -12,10 +12,15 @@
 import pathlib
 import re
 
-import pyds9
+from typing import TYPE_CHECKING
+
 from clu import AMQPClient, AMQPReply
 
 
+if TYPE_CHECKING:
+    from pyds9 import DS9
+
+
 CAMERAS = [
     "sci.west",
     "sci.east",
@@ -95,9 +100,17 @@ async def handle_reply(reply: AMQPReply):
         await asyncio.sleep(1)
 
 
-def ds9_clear_frames(ds9: pyds9.DS9 | None = None, ds9_target: str = "DS9:*"):
+def ds9_clear_frames(ds9: DS9 | None = None, ds9_target: str = "DS9:*"):
     """Clears all frames in DS9."""
 
+    try:
+        import pyds9
+    except ImportError:
+        raise ImportError(
+            "pyds9 is not installed. You can install it manually or run"
+            "pip install lvmopstools[ds9]"
+        )
+
     if ds9 is None:
         ds9 = pyds9.DS9(target=ds9_target)
 
@@ -108,7 +121,7 @@ def ds9_clear_frames(ds9: pyds9.DS9 | None = None, ds9_target: str = "DS9:*"):
 
 def ds9_display_frames(
     files: list[str | pathlib.Path] | dict[str, str | pathlib.Path | None],
-    ds9: pyds9.DS9 | None = None,
+    ds9: DS9 | None = None,
     order=CAMERAS,
     ds9_target: str = "DS9:*",
     show_all_frames=True,
@@ -120,6 +133,14 @@ def ds9_display_frames(
 ):
     """Displays a series of images in DS9."""
 
+    try:
+        import pyds9
+    except ImportError:
+        raise ImportError(
+            "pyds9 is not installed. You can install it manually or run"
+            "pip install lvmopstools[ds9]"
+        )
+
     if ds9 is None:
         ds9 = pyds9.DS9(target=ds9_target)