optional pickleshare (#14217)

IPython/core/interactiveshell.py

@@ -37,7 +37,28 b' from typing import List as ListType, Dict as DictType, Any as AnyType'
 from typing import Optional, Sequence, Tuple
 from warnings import warn
 
+try:
 from pickleshare import PickleShareDB
+except ModuleNotFoundError:
+
+    class PickleShareDB:  # type: ignore [no-redef]
+        def __init__(self, path):
+            pass
+
+        def get(self, key, default):
+            warn(
+                f"using {key} requires you to install the `pickleshare` library.",
+                stacklevel=2,
+            )
+            return default
+
+        def __setitem__(self, key, value):
+            warn(
+                f"using {key} requires you to install the `pickleshare` library.",
+                stacklevel=2,
+            )
+
+
 from tempfile import TemporaryDirectory
 from traitlets import (
     Any,

setup.cfg

@@ -36,7 +36,6 b' install_requires ='
     jedi>=0.16
     matplotlib-inline
     pexpect>4.3; sys_platform != "win32"
-    pickleshare
     prompt_toolkit>=3.0.30,<3.1.0,!=3.0.37
     pygments>=2.4.0
     stack_data
@@ -76,6 +75,7 b' test ='
     pytest<7.1
     pytest-asyncio
     testpath
+    pickleshare
 test_extra =
     %(test)s
     curio