Fix param.ipython auto-import

param/_utils.py

@@ -546,3 +546,11 @@ def exceptions_summarized():
         import sys
         etype, value, tb = sys.exc_info()
         print(f"{etype.__name__}: {value}", file=sys.stderr)
+
+
+def _in_ipython():
+    try:
+        get_ipython()
+        return True
+    except NameError:
+        return False

param/depends.py

@@ -1,5 +1,3 @@
-import weakref
-
 from collections import defaultdict
 from functools import wraps
 
@@ -8,25 +6,6 @@
 )
 from ._utils import accept_arguments, iscoroutinefunction
 
-_display_accessors = {}
-_reactive_display_objs = weakref.WeakSet()
-
-def register_display_accessor(name, accessor, force=False):
-    if name in _display_accessors and not force:
-        raise KeyError(
-            'Display accessor {name!r} already registered. Override it '
-            'by setting force=True or unregister the existing accessor first.')
-    _display_accessors[name] = accessor
-    for fn in _reactive_display_objs:
-        setattr(fn, name, accessor(fn))
-
-def unregister_display_accessor(name):
-    if name not in _display_accessors:
-        raise KeyError('No such display accessor: {name!r}')
-    del _display_accessors[name]
-    for fn in _reactive_display_objs:
-        delattr(fn, name)
-
 
 @accept_arguments
 def depends(func, *dependencies, watch=False, on_init=False, **kw):

param/display.py

@@ -0,0 +1,20 @@
+import weakref
+
+_display_accessors = {}
+_reactive_display_objs = weakref.WeakSet()
+
+def register_display_accessor(name, accessor, force=False):
+    if name in _display_accessors and not force:
+        raise KeyError(
+            'Display accessor {name!r} already registered. Override it '
+            'by setting force=True or unregister the existing accessor first.')
+    _display_accessors[name] = accessor
+    for fn in _reactive_display_objs:
+        setattr(fn, name, accessor(fn))
+
+def unregister_display_accessor(name):
+    if name not in _display_accessors:
+        raise KeyError('No such display accessor: {name!r}')
+    del _display_accessors[name]
+    for fn in _reactive_display_objs:
+        delattr(fn, name)

param/ipython.py

@@ -24,9 +24,7 @@
 
 import param
 
-from param.depends import depends, register_display_accessor
-from param.parameterized import resolve_ref
-from param.reactive import rx
+from param.display import register_display_accessor
 
 
 # Whether to generate warnings when misformatted docstrings are found
@@ -365,6 +363,10 @@ def __init__(self, reactive):
         self._reactive = reactive
 
     def __call__(self):
+        from param.depends import depends
+        from param.parameterized import resolve_ref
+        from param.reactive import rx
+
         if isinstance(self._reactive, rx):
             cb = self._reactive._callback
             @depends(*self._reactive._params, watch=True)

param/parameterized.py

@@ -45,6 +45,7 @@
     _deprecated,
     _deprecate_positional_args,
     _dict_update,
+    _in_ipython,
     _is_auto_name,
     _is_mutable_container,
     _recursive_repr,
@@ -54,17 +55,19 @@
     descendents,
 )
 
-try:
-    get_ipython()
-except NameError:
-    param_pager = None
-else:
+# Ideally setting param_pager would be in __init__.py but param_pager is
+# needed on import to create the Parameterized class, so it'd need to precede
+# importing parameterized.py in __init__.py which would be a little weird.
+if _in_ipython():
     # In case the optional ipython module is unavailable
     try:
         from .ipython import ParamPager
         param_pager = ParamPager(metaclass=True)  # Generates param description
-    except:
+    except ImportError:
         param_pager = None
+else:
+    param_pager = None
+
 
 from inspect import getfullargspec
 

param/reactive.py

@@ -90,9 +90,8 @@
 from typing import Any, Callable, Optional
 
 from . import Event
-from .depends import (
-    _display_accessors, _reactive_display_objs, depends,
-)
+from .depends import depends
+from .display import _display_accessors, _reactive_display_objs
 from .parameterized import (
     Parameter, Parameterized, eval_function_with_deps, get_method_owner,
     register_reference_transform, resolve_ref, resolve_value, transform_reference

tests/testipythonmagic.py

@@ -14,9 +14,6 @@
     if os.getenv('PARAM_TEST_IPYTHON','0') == '1':
         raise ImportError("PARAM_TEST_IPYTHON=1 but ipython not available.")
 
-# TODO: is the below actually true?
-
-# SkipTest will be raised if IPython unavailable
 from param.ipython import ParamPager
 
 test1_repr = """\x1b[1;32mParameters of 'TestClass'\n=========================\n\x1b[0m\n\x1b[1;31mParameters changed from their default values are marked in red.\x1b[0m\n\x1b[1;36mSoft bound values are marked in cyan.\x1b[0m\nC/V= Constant/Variable, RO/RW = ReadOnly/ReadWrite, AN=Allow None\n\n\x1b[1;34mNameValue   Type     Bounds      Mode  \x1b[0m\n\nu    4    Number                V RW  \nw    4    Number                C RO  \nv    4    Number                C RW  \nx   None  String              V RW AN \ny    4    Number  (-1, None)    V RW  \nz    4    Number  (-1, 100)     V RW  \n\n\x1b[1;32mParameter docstrings:\n=====================\x1b[0m\n\n\x1b[1;34mu: < No docstring available >\x1b[0m\n\x1b[1;31mw: < No docstring available >\x1b[0m\n\x1b[1;34mv: < No docstring available >\x1b[0m\n\x1b[1;31mx: < No docstring available >\x1b[0m\n\x1b[1;34my: < No docstring available >\x1b[0m\n\x1b[1;31mz: < No docstring available >\x1b[0m"""