rename common.txt to core.txt and added import message in try except

requirements.txt

@@ -1 +1 @@
--r requirements/common.txt
+-r requirements/core.txt

requirements/dev.txt

@@ -1,6 +1,6 @@
 # core, plotly and tests
 
--r common.txt
+-r core.txt
 -r plotly.txt
 
 # required for development

requirements/plotly.txt

@@ -1,5 +1,5 @@
 # core + plotly plotting, no tests
--r common.txt
+-r core.txt
 
 plotly==5.5.0
 dash

setup.py

@@ -16,8 +16,8 @@
 with open("README.md", "r", encoding="utf-8") as fh:
     long_description = fh.read()
 
-with open("requirements/common.txt") as f:
-    required = f.read().splitlines()
+with open("requirements/core.txt") as f:
+    core_required = f.read().splitlines()
 
 with open("requirements/plotly.txt") as f:
     plotly_required = f.read().splitlines()
@@ -40,10 +40,8 @@
         "License :: OSI Approved :: MIT License",
         "Operating System :: OS Independent",
     ],
-    # package_dir={"": ""},
-    # packages=[PACKAGE_NAME],
     packages=setuptools.find_packages(),
     python_requires=">=3.6",
-    install_requires=required,
+    install_requires=core_required,
     extras_require={"plotly": plotly_required},
 )

tidy3d/log.py

@@ -66,6 +66,10 @@ class DataError(Tidy3dError):
     """Error accessing data."""
 
 
+class Tidy3dImportError(Tidy3dError):
+    """Error importing a package needed for tidy3d."""
+
+
 """ Logging functions """
 
 

tidy3d/plugins/webplots/__init__.py

@@ -1,3 +1,19 @@
 """Import post run visualization app and Simulation plotting through plotly."""
+
+from ...log import Tidy3dImportError
+
+# try to get the plotly packages, otherwise print a helpful error message.
+try:
+    from jupyter_dash import JupyterDash
+    from dash import Dash
+    import plotly.graph_objects as go
+except ImportError as e:
+    raise Tidy3dImportError(
+        "Could not import plotly requirements. "
+        "Ensure that tidy3d is installed with [plotly] requirements specified. "
+        '``pip install "tidy3d-beta[plotly]" or `pip install -e ".[plotly]". '
+        "Or, install the dependencies directly with `pip install -r requirements/plotly.txt`"
+    ) from e
+
 from .app import SimulationDataApp
 from .simulation import SimulationPlotly