Simplify __all__ extension

Co-authored-by: Adam Turner <[email protected]>

Author: picnixz

Lib/pickle.py

@@ -187,10 +187,7 @@ def __init__(self, value):
 NEXT_BUFFER      = b'\x97'  # push next out-of-band buffer
 READONLY_BUFFER  = b'\x98'  # make top of stack readonly
 
-__all__.extend([
-    x for x in dir()
-    if x.isupper() and x.isidentifier() and not x.startswith('_')
-])
+__all__.extend(x for x in dir() if x.isupper() and not x.startswith('_'))
 
 class _Framer: