Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/pip/_internal/utils/virtualenv.py: 44%

1import logging 

2import os 

3import re 

4import site 

5import sys 

6from typing import List, Optional 

7 

8logger = logging.getLogger(__name__) 

9_INCLUDE_SYSTEM_SITE_PACKAGES_REGEX = re.compile( 

10 r"include-system-site-packages\s*=\s*(?P<value>true|false)" 

11) 

12 

13 

14def _running_under_venv() -> bool: 

15 """Checks if sys.base_prefix and sys.prefix match. 

16 

17 This handles PEP 405 compliant virtual environments. 

18 """ 

19 return sys.prefix != getattr(sys, "base_prefix", sys.prefix) 

20 

21 

22def _running_under_legacy_virtualenv() -> bool: 

23 """Checks if sys.real_prefix is set. 

24 

25 This handles virtual environments created with pypa's virtualenv. 

26 """ 

27 # pypa/virtualenv case 

28 return hasattr(sys, "real_prefix") 

29 

30 

31def running_under_virtualenv() -> bool: 

32 """True if we're running inside a virtual environment, False otherwise.""" 

33 return _running_under_venv() or _running_under_legacy_virtualenv() 

34 

35 

36def _get_pyvenv_cfg_lines() -> Optional[List[str]]: 

37 """Reads {sys.prefix}/pyvenv.cfg and returns its contents as list of lines 

38 

39 Returns None, if it could not read/access the file. 

40 """ 

41 pyvenv_cfg_file = os.path.join(sys.prefix, "pyvenv.cfg") 

42 try: 

43 # Although PEP 405 does not specify, the built-in venv module always 

44 # writes with UTF-8. (pypa/pip#8717) 

45 with open(pyvenv_cfg_file, encoding="utf-8") as f: 

46 return f.read().splitlines() # avoids trailing newlines 

47 except OSError: 

48 return None 

49 

50 

51def _no_global_under_venv() -> bool: 

52 """Check `{sys.prefix}/pyvenv.cfg` for system site-packages inclusion 

53 

54 PEP 405 specifies that when system site-packages are not supposed to be 

55 visible from a virtual environment, `pyvenv.cfg` must contain the following 

56 line: 

57 

58 include-system-site-packages = false 

59 

60 Additionally, log a warning if accessing the file fails. 

61 """ 

62 cfg_lines = _get_pyvenv_cfg_lines() 

63 if cfg_lines is None: 

64 # We're not in a "sane" venv, so assume there is no system 

65 # site-packages access (since that's PEP 405's default state). 

66 logger.warning( 

67 "Could not access 'pyvenv.cfg' despite a virtual environment " 

68 "being active. Assuming global site-packages is not accessible " 

69 "in this environment." 

70 ) 

71 return True 

72 

73 for line in cfg_lines: 

74 match = _INCLUDE_SYSTEM_SITE_PACKAGES_REGEX.match(line) 

75 if match is not None and match.group("value") == "false": 

76 return True 

77 return False 

78 

79 

80def _no_global_under_legacy_virtualenv() -> bool: 

81 """Check if "no-global-site-packages.txt" exists beside site.py 

82 

83 This mirrors logic in pypa/virtualenv for determining whether system 

84 site-packages are visible in the virtual environment. 

85 """ 

86 site_mod_dir = os.path.dirname(os.path.abspath(site.__file__)) 

87 no_global_site_packages_file = os.path.join( 

88 site_mod_dir, 

89 "no-global-site-packages.txt", 

90 ) 

91 return os.path.exists(no_global_site_packages_file) 

92 

93 

94def virtualenv_no_global() -> bool: 

95 """Returns a boolean, whether running in venv with no system site-packages.""" 

96 # PEP 405 compliance needs to be checked first since virtualenv >=20 would 

97 # return True for both checks, but is only able to use the PEP 405 config. 

98 if _running_under_venv(): 

99 return _no_global_under_venv() 

100 

101 if _running_under_legacy_virtualenv(): 

102 return _no_global_under_legacy_virtualenv() 

103 

104 return False