Close #13062: Add inspect.getclosurevars to simplify testing stateful closures
diff --git a/Lib/inspect.py b/Lib/inspect.py
index 484c9c3..dd2de64 100644
--- a/Lib/inspect.py
+++ b/Lib/inspect.py
@@ -42,6 +42,7 @@
import types
import warnings
import functools
+import builtins
from operator import attrgetter
from collections import namedtuple, OrderedDict
@@ -1036,6 +1037,59 @@
_missing_arguments(f_name, kwonlyargs, False, arg2value)
return arg2value
+ClosureVars = namedtuple('ClosureVars', 'nonlocals globals builtins unbound')
+
+def getclosurevars(func):
+ """
+ Get the mapping of free variables to their current values.
+
+ Returns a named tuple of dics mapping the current nonlocal, global
+ and builtin references as seen by the body of the function. A final
+ set of unbound names that could not be resolved is also provided.
+ """
+
+ if ismethod(func):
+ func = func.__func__
+
+ if not isfunction(func):
+ raise TypeError("'{!r}' is not a Python function".format(func))
+
+ code = func.__code__
+ # Nonlocal references are named in co_freevars and resolved
+ # by looking them up in __closure__ by positional index
+ if func.__closure__ is None:
+ nonlocal_vars = {}
+ else:
+ nonlocal_vars = {
+ var : cell.cell_contents
+ for var, cell in zip(code.co_freevars, func.__closure__)
+ }
+
+ # Global and builtin references are named in co_names and resolved
+ # by looking them up in __globals__ or __builtins__
+ global_ns = func.__globals__
+ builtin_ns = global_ns.get("__builtins__", builtins.__dict__)
+ if ismodule(builtin_ns):
+ builtin_ns = builtin_ns.__dict__
+ global_vars = {}
+ builtin_vars = {}
+ unbound_names = set()
+ for name in code.co_names:
+ if name in ("None", "True", "False"):
+ # Because these used to be builtins instead of keywords, they
+ # may still show up as name references. We ignore them.
+ continue
+ try:
+ global_vars[name] = global_ns[name]
+ except KeyError:
+ try:
+ builtin_vars[name] = builtin_ns[name]
+ except KeyError:
+ unbound_names.add(name)
+
+ return ClosureVars(nonlocal_vars, global_vars,
+ builtin_vars, unbound_names)
+
# -------------------------------------------------- stack frame extraction
Traceback = namedtuple('Traceback', 'filename lineno function code_context index')