Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/pkg_resources/extern/__init__.py: 8%

1import importlib.util 

2import sys 

3 

4 

5class VendorImporter: 

6 """ 

7 A PEP 302 meta path importer for finding optionally-vendored 

8 or otherwise naturally-installed packages from root_name. 

9 """ 

10 

11 def __init__(self, root_name, vendored_names=(), vendor_pkg=None): 

12 self.root_name = root_name 

13 self.vendored_names = set(vendored_names) 

14 self.vendor_pkg = vendor_pkg or root_name.replace('extern', '_vendor') 

15 

16 @property 

17 def search_path(self): 

18 """ 

19 Search first the vendor package then as a natural package. 

20 """ 

21 yield self.vendor_pkg + '.' 

22 yield '' 

23 

24 def _module_matches_namespace(self, fullname): 

25 """Figure out if the target module is vendored.""" 

26 root, base, target = fullname.partition(self.root_name + '.') 

27 return not root and any(map(target.startswith, self.vendored_names)) 

28 

29 def load_module(self, fullname): 

30 """ 

31 Iterate over the search path to locate and load fullname. 

32 """ 

33 root, base, target = fullname.partition(self.root_name + '.') 

34 for prefix in self.search_path: 

35 try: 

36 extant = prefix + target 

37 __import__(extant) 

38 mod = sys.modules[extant] 

39 sys.modules[fullname] = mod 

40 return mod 

41 except ImportError: 

42 pass 

43 else: 

44 raise ImportError( 

45 "The '{target}' package is required; " 

46 "normally this is bundled with this package so if you get " 

47 "this warning, consult the packager of your " 

48 "distribution.".format(**locals()) 

49 ) 

50 

51 def create_module(self, spec): 

52 return self.load_module(spec.name) 

53 

54 def exec_module(self, module): 

55 pass 

56 

57 def find_spec(self, fullname, path=None, target=None): 

58 """Return a module spec for vendored names.""" 

59 return ( 

60 importlib.util.spec_from_loader(fullname, self) 

61 if self._module_matches_namespace(fullname) 

62 else None 

63 ) 

64 

65 def install(self): 

66 """ 

67 Install this importer into sys.meta_path if not already present. 

68 """ 

69 if self not in sys.meta_path: 

70 sys.meta_path.append(self) 

71 

72 

73names = ( 

74 'packaging', 

75 'platformdirs', 

76 'jaraco', 

77 'importlib_resources', 

78 'more_itertools', 

79 'backports', 

80) 

81VendorImporter(__name__, names).install()