Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/IPython/core/builtin_trap.py: 33%

1""" 

2A context manager for managing things injected into :mod:`builtins`. 

3""" 

4# Copyright (c) IPython Development Team. 

5# Distributed under the terms of the Modified BSD License. 

6import builtins as builtin_mod 

7 

8from traitlets.config.configurable import Configurable 

9 

10from traitlets import Instance 

11 

12 

13class __BuiltinUndefined(object): pass 

14BuiltinUndefined = __BuiltinUndefined() 

15 

16class __HideBuiltin(object): pass 

17HideBuiltin = __HideBuiltin() 

18 

19 

20class BuiltinTrap(Configurable): 

21 

22 shell = Instance('IPython.core.interactiveshell.InteractiveShellABC', 

23 allow_none=True) 

24 

25 def __init__(self, shell=None): 

26 super(BuiltinTrap, self).__init__(shell=shell, config=None) 

27 self._orig_builtins = {} 

28 # We define this to track if a single BuiltinTrap is nested. 

29 # Only turn off the trap when the outermost call to __exit__ is made. 

30 self._nested_level = 0 

31 self.shell = shell 

32 # builtins we always add - if set to HideBuiltin, they will just 

33 # be removed instead of being replaced by something else 

34 self.auto_builtins = {'exit': HideBuiltin, 

35 'quit': HideBuiltin, 

36 'get_ipython': self.shell.get_ipython, 

37 } 

38 

39 def __enter__(self): 

40 if self._nested_level == 0: 

41 self.activate() 

42 self._nested_level += 1 

43 # I return self, so callers can use add_builtin in a with clause. 

44 return self 

45 

46 def __exit__(self, type, value, traceback): 

47 if self._nested_level == 1: 

48 self.deactivate() 

49 self._nested_level -= 1 

50 # Returning False will cause exceptions to propagate 

51 return False 

52 

53 def add_builtin(self, key, value): 

54 """Add a builtin and save the original.""" 

55 bdict = builtin_mod.__dict__ 

56 orig = bdict.get(key, BuiltinUndefined) 

57 if value is HideBuiltin: 

58 if orig is not BuiltinUndefined: #same as 'key in bdict' 

59 self._orig_builtins[key] = orig 

60 del bdict[key] 

61 else: 

62 self._orig_builtins[key] = orig 

63 bdict[key] = value 

64 

65 def remove_builtin(self, key, orig): 

66 """Remove an added builtin and re-set the original.""" 

67 if orig is BuiltinUndefined: 

68 del builtin_mod.__dict__[key] 

69 else: 

70 builtin_mod.__dict__[key] = orig 

71 

72 def activate(self): 

73 """Store ipython references in the __builtin__ namespace.""" 

74 

75 add_builtin = self.add_builtin 

76 for name, func in self.auto_builtins.items(): 

77 add_builtin(name, func) 

78 

79 def deactivate(self): 

80 """Remove any builtins which might have been added by add_builtins, or 

81 restore overwritten ones to their previous values.""" 

82 remove_builtin = self.remove_builtin 

83 for key, val in self._orig_builtins.items(): 

84 remove_builtin(key, val) 

85 self._orig_builtins.clear() 

86 self._builtins_added = False