restart kernel daemon when non-package Python modules change

news/changelog-1.4.md

@@ -159,6 +159,7 @@
 - Only search for Julia conda installation when the engine language is Julia
 - Support for `plotly-connected` option to determine where Plotly is embedded or loaded from CDN
 - Reduce default margins for Plotly figures (t=30,r=0,b=0,l=0)
+- Restart kernel daemon when non-package Python modules change
 
 ## Knitr
 

src/resources/jupyter/lang/python/cleanup.py

@@ -1,3 +1,30 @@
 
 # reset state
 %reset
+
+import sys
+import types
+import os
+import json
+
+# NOTE: the kernel_deps code is repeated in the setup.py file
+# (we can't easily share this code b/c of the way it is run).
+# If you edit this code also edit the same code in setup.py!
+
+kernel_deps = dict()
+for module in list(sys.modules.values()):
+  # Some modules play games with sys.modules (e.g. email/__init__.py
+  # in the standard library), and occasionally this can cause strange
+  # failures in getattr.  Just ignore anything that's not an ordinary
+  # module.
+  if not isinstance(module, types.ModuleType):
+    continue
+  path = getattr(module, "__file__", None)
+  if not path:
+    continue
+  if path.endswith(".pyc") or path.endswith(".pyo"):
+    path = path[:-1]
+  if not os.path.exists(path):
+    continue
+  kernel_deps[path] = os.stat(path).st_mtime
+print(json.dumps(kernel_deps))

src/resources/jupyter/lang/python/setup.py

@@ -62,6 +62,10 @@
   from IPython.core.interactiveshell import InteractiveShell
   InteractiveShell.ast_node_interactivity = interactivity
 
+# NOTE: the kernel_deps code is repeated in the cleanup.py file
+# (we can't easily share this code b/c of the way it is run).
+# If you edit this code also edit the same code in cleanup.py!
+
 # output kernel dependencies
 kernel_deps = dict()
 for module in list(sys.modules.values()):

src/resources/jupyter/notebook.py

@@ -225,19 +225,16 @@ def notebook_execute(options, status):
 
       # if this was the setup cell, see if we need to exit b/c dependencies are out of date
       if index == 0:
-         kernel_deps = nb_kernel_depenencies(cell)
-         if kernel_deps:
-            if hasattr(notebook_execute, "kernel_deps"):
+         # confirm kernel_deps haven't changed (restart if they have)
+         if hasattr(notebook_execute, "kernel_deps"):
+            kernel_deps = nb_kernel_depenencies(cell)
+            if kernel_deps:
                for path in kernel_deps.keys():
                   if path in notebook_execute.kernel_deps.keys():
                      if notebook_execute.kernel_deps[path] != kernel_deps[path]:
                         raise RestartKernel
                   else:
                      notebook_execute.kernel_deps[path] = kernel_deps[path]
-            else:
-               notebook_execute.kernel_deps = kernel_deps
-         else:
-            notebook_execute.kernel_deps = {}
 
          # we are done w/ setup (with no restarts) so it's safe to print 'Executing...'
          if not quiet:
@@ -284,6 +281,14 @@ def notebook_execute(options, status):
    )
    nb.cells.pop()
 
+   # record kernel deps after execution (picks up imports that occurred
+   # witihn the notebook cells)
+   kernel_deps = nb_kernel_depenencies(cleanup_cell)
+   if kernel_deps:
+      notebook_execute.kernel_deps = kernel_deps
+   else:
+      notebook_execute.kernel_deps = {}
+
    # progress
    if not quiet:
       status("\n")