fork(1) download 
  1. import inspect
  2. import types
  3.  
  4. def get_cc():
  5. 	"""Generate the current continuation."""
  6. 	up_frame = inspect.currentframe().f_back
  7.  
  8. 	def copy_code(base, co_code):
  9. 		"""Copy a code object, but change the code"""
  10. 		return types.CodeType(base.co_argcount,
  11. 		                      base.co_kwonlyargcount,
  12. 		                      base.co_nlocals,
  13. 		                      base.co_stacksize,
  14. 		                      base.co_flags,
  15. 		                      co_code,
  16. 		                      base.co_consts,
  17. 		                      base.co_names,
  18. 		                      base.co_varnames,
  19. 		                      base.co_filename,
  20. 		                      base.co_name,
  21. 		                      base.co_firstlineno,
  22. 		                      base.co_lnotab,
  23. 		                      base.co_freevars,
  24. 		                      base.co_cellvars)
  25.  
  26. 	# In this case, the call to get_cc and the resulting assignment to a global variable
  27. 	# is 4 bytes worth of bytecode.
  28. 	new_code = copy_code(up_frame.f_code, up_frame.f_code.co_code[up_frame.f_lasti + 6:])
  29. 	return new_code
  30.  
  31.  
  32. def call_cc(cont):
  33. 	"""Call the current continuation"""
  34. 	exec(cont)
  35.  
  36.  
  37. cc, bar = None, 0
  38.  
  39. def func():
  40. 	global cc
  41. 	print("This should show only once")
  42. 	cc = get_cc()
  43. 	global bar
  44. 	print(bar)
  45. 	bar += 1
  46.  
  47. func()
  48. call_cc(cc)
  49. call_cc(cc)
  50. call_cc(cc)
Success #stdin #stdout 0.03s 30952KB
comments (?)
stdin 
Standard input is empty
stdout 
This should show only once
0
1
2
3
https://ideone.com/J1KesT
language:
Python 3 (python  3.12)
created:
7 years ago
visibility:
secret

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