def getsitepackages():
"""
Return only one item as list with one item.
"""
# For now used only on Windows. Raise Exception for other platforms.
if is_win:
pths = [os.path.join(sys.prefix, 'Lib', 'site-packages')]
# Include Real sys.prefix for virtualenv.
if is_virtualenv:
pths.append(os.path.join(base_prefix, 'Lib', 'site-packages'))
return pths
else:
# TODO Implement for Python 2.6 on other platforms.
raise NotImplementedError()
# Function to reload a module - used to reload module 'PyInstaller.config' for tests.
# imp module is deprecated since Python 3.4.
python类base_prefix()的实例源码
def test_user_similar(self):
# Issue #8759: make sure the posix scheme for the users
# is similar to the global posix_prefix one
base = get_config_var('base')
user = get_config_var('userbase')
# the global scheme mirrors the distinction between prefix and
# exec-prefix but not the user scheme, so we have to adapt the paths
# before comparing (issue #9100)
adapt = sys.base_prefix != sys.base_exec_prefix
for name in ('stdlib', 'platstdlib', 'purelib', 'platlib'):
global_path = get_path(name, 'posix_prefix')
if adapt:
global_path = global_path.replace(sys.exec_prefix, sys.base_prefix)
base = base.replace(sys.exec_prefix, sys.base_prefix)
elif sys.base_prefix != sys.prefix:
# virtual environment? Likewise, we have to adapt the paths
# before comparing
global_path = global_path.replace(sys.base_prefix, sys.prefix)
base = base.replace(sys.base_prefix, sys.prefix)
user_path = get_path(name, 'posix_user')
self.assertEqual(user_path, global_path.replace(base, user, 1))
def test_prefixes(self):
"""
Test that the prefix values are as expected.
"""
#check our prefixes
self.assertEqual(sys.base_prefix, sys.prefix)
self.assertEqual(sys.base_exec_prefix, sys.exec_prefix)
# check a venv's prefixes
shutil.rmtree(self.env_dir)
self.run_with_capture(venv.create, self.env_dir)
envpy = os.path.join(self.env_dir, self.bindir, self.exe)
cmd = [envpy, '-c', None]
for prefix, expected in (
('prefix', self.env_dir),
('prefix', self.env_dir),
('base_prefix', sys.prefix),
('base_exec_prefix', sys.exec_prefix)):
cmd[2] = 'import sys; print(sys.%s)' % prefix
p = subprocess.Popen(cmd, stdout=subprocess.PIPE,
stderr=subprocess.PIPE)
out, err = p.communicate()
self.assertEqual(out.strip(), expected.encode())
def test_user_similar(self):
# Issue #8759: make sure the posix scheme for the users
# is similar to the global posix_prefix one
base = get_config_var('base')
user = get_config_var('userbase')
# the global scheme mirrors the distinction between prefix and
# exec-prefix but not the user scheme, so we have to adapt the paths
# before comparing (issue #9100)
adapt = sys.base_prefix != sys.base_exec_prefix
for name in ('stdlib', 'platstdlib', 'purelib', 'platlib'):
global_path = get_path(name, 'posix_prefix')
if adapt:
global_path = global_path.replace(sys.exec_prefix, sys.base_prefix)
base = base.replace(sys.exec_prefix, sys.base_prefix)
elif sys.base_prefix != sys.prefix:
# virtual environment? Likewise, we have to adapt the paths
# before comparing
global_path = global_path.replace(sys.base_prefix, sys.prefix)
base = base.replace(sys.base_prefix, sys.prefix)
user_path = get_path(name, 'posix_user')
self.assertEqual(user_path, global_path.replace(base, user, 1))
def test_prefixes(self):
"""
Test that the prefix values are as expected.
"""
#check our prefixes
self.assertEqual(sys.base_prefix, sys.prefix)
self.assertEqual(sys.base_exec_prefix, sys.exec_prefix)
# check a venv's prefixes
rmtree(self.env_dir)
self.run_with_capture(venv.create, self.env_dir)
envpy = os.path.join(self.env_dir, self.bindir, self.exe)
cmd = [envpy, '-c', None]
for prefix, expected in (
('prefix', self.env_dir),
('prefix', self.env_dir),
('base_prefix', sys.prefix),
('base_exec_prefix', sys.exec_prefix)):
cmd[2] = 'import sys; print(sys.%s)' % prefix
p = subprocess.Popen(cmd, stdout=subprocess.PIPE,
stderr=subprocess.PIPE)
out, err = p.communicate()
self.assertEqual(out.strip(), expected.encode())
def test_prefixes(self):
"""
Test that the prefix values are as expected.
"""
#check our prefixes
self.assertEqual(sys.base_prefix, sys.prefix)
self.assertEqual(sys.base_exec_prefix, sys.exec_prefix)
# check a venv's prefixes
shutil.rmtree(self.env_dir)
self.run_with_capture(venv.create, self.env_dir)
envpy = os.path.join(self.env_dir, self.bindir, self.exe)
cmd = [envpy, '-c', None]
for prefix, expected in (
('prefix', self.env_dir),
('prefix', self.env_dir),
('base_prefix', sys.prefix),
('base_exec_prefix', sys.exec_prefix)):
cmd[2] = 'import sys; print(sys.%s)' % prefix
p = subprocess.Popen(cmd, stdout=subprocess.PIPE,
stderr=subprocess.PIPE)
out, err = p.communicate()
self.assertEqual(out.strip(), expected.encode())
def __init__(self, name, folder=None, respect_venv=False):
if folder is None:
folder = JSONKVStore.DefaultFolder
#If we are relative to a virtual environment, place the registry into that virtual env
#Support both virtualenv and pythnon 3 venv
if respect_venv and hasattr(sys, 'real_prefix'):
folder = sys.prefix
elif respect_venv and hasattr(sys, 'base_prefix') and sys.base_prefix != sys.prefix:
folder = sys.prefix
if not os.path.exists(folder):
os.makedirs(folder, 0755)
jsonfile = os.path.join(folder, name)
self.file = jsonfile
def __init__(self, name, folder=None, respect_venv=False):
if folder is None:
folder = SQLiteKVStore.DefaultFolder
#If we are relative to a virtual environment, place the registry into that virtual env
#Support both virtualenv and pythnon 3 venv
if respect_venv and hasattr(sys, 'real_prefix'):
folder = sys.prefix
elif respect_venv and hasattr(sys, 'base_prefix') and sys.base_prefix != sys.prefix:
folder = sys.prefix
if not os.path.exists(folder):
os.makedirs(folder, 0755)
dbfile = os.path.join(folder, name)
self.connection = sqlite3.connect(dbfile)
self.cursor = self.connection.cursor()
self.file = dbfile
self._setup_table()
def getsitepackages():
"""
Return only one item as list with one item.
"""
# For now used only on Windows. Raise Exception for other platforms.
if is_win:
pths = [os.path.join(sys.prefix, 'Lib', 'site-packages')]
# Include Real sys.prefix for virtualenv.
if is_virtualenv:
pths.append(os.path.join(base_prefix, 'Lib', 'site-packages'))
return pths
else:
# TODO Implement for Python 2.6 on other platforms.
raise NotImplementedError()
# Function to reload a module - used to reload module 'PyInstaller.config' for tests.
# imp module is deprecated since Python 3.4.
def tearDown(self):
if sys.version < "2.6" or hasattr(sys, 'real_prefix') or (hasattr(sys, 'base_prefix') and sys.base_prefix != sys.prefix):
return
os.chdir(self.old_cwd)
shutil.rmtree(self.dir)
shutil.rmtree(site.USER_BASE)
shutil.rmtree(site.USER_SITE)
site.USER_BASE = self.old_base
site.USER_SITE = self.old_site
def tearDown(self):
if sys.version < "2.6" or hasattr(sys, 'real_prefix') or (hasattr(sys, 'base_prefix') and sys.base_prefix != sys.prefix):
return
os.chdir(self.old_cwd)
shutil.rmtree(self.dir)
shutil.rmtree(site.USER_BASE)
shutil.rmtree(site.USER_SITE)
site.USER_BASE = self.old_base
site.USER_SITE = self.old_site
def setup_detect_python2():
"""
Call this before using the refactoring tools to create them on demand
if needed.
"""
if None in [RTs._rt_py2_detect, RTs._rtp_py2_detect]:
RTs._rt_py2_detect = RefactoringTool(py2_detect_fixers)
RTs._rtp_py2_detect = RefactoringTool(py2_detect_fixers,
{'print_function': True})
# We need to find a prefix for the standard library, as we don't want to
# process any files there (they will already be Python 3).
#
# The following method is used by Sanjay Vinip in uprefix. This fails for
# ``conda`` environments:
# # In a non-pythonv virtualenv, sys.real_prefix points to the installed Python.
# # In a pythonv venv, sys.base_prefix points to the installed Python.
# # Outside a virtual environment, sys.prefix points to the installed Python.
# if hasattr(sys, 'real_prefix'):
# _syslibprefix = sys.real_prefix
# else:
# _syslibprefix = getattr(sys, 'base_prefix', sys.prefix)
# Instead, we use the portion of the path common to both the stdlib modules
# ``math`` and ``urllib``.
def change_prefix(filename, dst_prefix):
prefixes = [sys.prefix]
if is_darwin:
prefixes.extend((
os.path.join("/Library/Python", sys.version[:3], "site-packages"),
os.path.join(sys.prefix, "Extras", "lib", "python"),
os.path.join("~", "Library", "Python", sys.version[:3], "site-packages"),
# Python 2.6 no-frameworks
os.path.join("~", ".local", "lib","python", sys.version[:3], "site-packages"),
# System Python 2.7 on OSX Mountain Lion
os.path.join("~", "Library", "Python", sys.version[:3], "lib", "python", "site-packages")))
if hasattr(sys, 'real_prefix'):
prefixes.append(sys.real_prefix)
if hasattr(sys, 'base_prefix'):
prefixes.append(sys.base_prefix)
prefixes = list(map(os.path.expanduser, prefixes))
prefixes = list(map(os.path.abspath, prefixes))
# Check longer prefixes first so we don't split in the middle of a filename
prefixes = sorted(prefixes, key=len, reverse=True)
filename = os.path.abspath(filename)
for src_prefix in prefixes:
if filename.startswith(src_prefix):
_, relpath = filename.split(src_prefix, 1)
if src_prefix != os.sep: # sys.prefix == "/"
assert relpath[0] == os.sep
relpath = relpath[1:]
return join(dst_prefix, relpath)
assert False, "Filename %s does not start with any of these prefixes: %s" % \
(filename, prefixes)
def tearDown(self):
if sys.version < "2.6" or hasattr(sys, 'real_prefix') or (hasattr(sys, 'base_prefix') and sys.base_prefix != sys.prefix):
return
os.chdir(self.old_cwd)
shutil.rmtree(self.dir)
shutil.rmtree(site.USER_BASE)
shutil.rmtree(site.USER_SITE)
site.USER_BASE = self.old_base
site.USER_SITE = self.old_site
def tearDown(self):
if sys.version < "2.6" or hasattr(sys, 'real_prefix') or (hasattr(sys, 'base_prefix') and sys.base_prefix != sys.prefix):
return
os.chdir(self.old_cwd)
shutil.rmtree(self.dir)
shutil.rmtree(site.USER_BASE)
shutil.rmtree(site.USER_SITE)
site.USER_BASE = self.old_base
site.USER_SITE = self.old_site
def setup_detect_python2():
"""
Call this before using the refactoring tools to create them on demand
if needed.
"""
if None in [RTs._rt_py2_detect, RTs._rtp_py2_detect]:
RTs._rt_py2_detect = RefactoringTool(py2_detect_fixers)
RTs._rtp_py2_detect = RefactoringTool(py2_detect_fixers,
{'print_function': True})
# We need to find a prefix for the standard library, as we don't want to
# process any files there (they will already be Python 3).
#
# The following method is used by Sanjay Vinip in uprefix. This fails for
# ``conda`` environments:
# # In a non-pythonv virtualenv, sys.real_prefix points to the installed Python.
# # In a pythonv venv, sys.base_prefix points to the installed Python.
# # Outside a virtual environment, sys.prefix points to the installed Python.
# if hasattr(sys, 'real_prefix'):
# _syslibprefix = sys.real_prefix
# else:
# _syslibprefix = getattr(sys, 'base_prefix', sys.prefix)
# Instead, we use the portion of the path common to both the stdlib modules
# ``math`` and ``urllib``.
def setup_detect_python2():
"""
Call this before using the refactoring tools to create them on demand
if needed.
"""
if None in [RTs._rt_py2_detect, RTs._rtp_py2_detect]:
RTs._rt_py2_detect = RefactoringTool(py2_detect_fixers)
RTs._rtp_py2_detect = RefactoringTool(py2_detect_fixers,
{'print_function': True})
# We need to find a prefix for the standard library, as we don't want to
# process any files there (they will already be Python 3).
#
# The following method is used by Sanjay Vinip in uprefix. This fails for
# ``conda`` environments:
# # In a non-pythonv virtualenv, sys.real_prefix points to the installed Python.
# # In a pythonv venv, sys.base_prefix points to the installed Python.
# # Outside a virtual environment, sys.prefix points to the installed Python.
# if hasattr(sys, 'real_prefix'):
# _syslibprefix = sys.real_prefix
# else:
# _syslibprefix = getattr(sys, 'base_prefix', sys.prefix)
# Instead, we use the portion of the path common to both the stdlib modules
# ``math`` and ``urllib``.
def tearDown(self):
if sys.version < "2.6" or hasattr(sys, 'real_prefix') or (hasattr(sys, 'base_prefix') and sys.base_prefix != sys.prefix):
return
os.chdir(self.old_cwd)
shutil.rmtree(self.dir)
shutil.rmtree(site.USER_BASE)
shutil.rmtree(site.USER_SITE)
site.USER_BASE = self.old_base
site.USER_SITE = self.old_site
def change_prefix(filename, dst_prefix):
prefixes = [sys.prefix]
if is_darwin:
prefixes.extend((
os.path.join("/Library/Python", sys.version[:3], "site-packages"),
os.path.join(sys.prefix, "Extras", "lib", "python"),
os.path.join("~", "Library", "Python", sys.version[:3], "site-packages"),
# Python 2.6 no-frameworks
os.path.join("~", ".local", "lib","python", sys.version[:3], "site-packages"),
# System Python 2.7 on OSX Mountain Lion
os.path.join("~", "Library", "Python", sys.version[:3], "lib", "python", "site-packages")))
if hasattr(sys, 'real_prefix'):
prefixes.append(sys.real_prefix)
if hasattr(sys, 'base_prefix'):
prefixes.append(sys.base_prefix)
prefixes = list(map(os.path.expanduser, prefixes))
prefixes = list(map(os.path.abspath, prefixes))
# Check longer prefixes first so we don't split in the middle of a filename
prefixes = sorted(prefixes, key=len, reverse=True)
filename = os.path.abspath(filename)
# On Windows, make sure drive letter is uppercase
if is_win and filename[0] in 'abcdefghijklmnopqrstuvwxyz':
filename = filename[0].upper() + filename[1:]
for i, prefix in enumerate(prefixes):
if is_win and prefix[0] in 'abcdefghijklmnopqrstuvwxyz':
prefixes[i] = prefix[0].upper() + prefix[1:]
for src_prefix in prefixes:
if filename.startswith(src_prefix):
_, relpath = filename.split(src_prefix, 1)
if src_prefix != os.sep: # sys.prefix == "/"
assert relpath[0] == os.sep
relpath = relpath[1:]
return join(dst_prefix, relpath)
assert False, "Filename %s does not start with any of these prefixes: %s" % \
(filename, prefixes)
def change_prefix(filename, dst_prefix):
prefixes = [sys.prefix]
if is_darwin:
prefixes.extend((
os.path.join("/Library/Python", sys.version[:3], "site-packages"),
os.path.join(sys.prefix, "Extras", "lib", "python"),
os.path.join("~", "Library", "Python", sys.version[:3], "site-packages"),
# Python 2.6 no-frameworks
os.path.join("~", ".local", "lib","python", sys.version[:3], "site-packages"),
# System Python 2.7 on OSX Mountain Lion
os.path.join("~", "Library", "Python", sys.version[:3], "lib", "python", "site-packages")))
if hasattr(sys, 'real_prefix'):
prefixes.append(sys.real_prefix)
if hasattr(sys, 'base_prefix'):
prefixes.append(sys.base_prefix)
prefixes = list(map(os.path.expanduser, prefixes))
prefixes = list(map(os.path.abspath, prefixes))
# Check longer prefixes first so we don't split in the middle of a filename
prefixes = sorted(prefixes, key=len, reverse=True)
filename = os.path.abspath(filename)
# On Windows, make sure drive letter is uppercase
if is_win and filename[0] in 'abcdefghijklmnopqrstuvwxyz':
filename = filename[0].upper() + filename[1:]
for i, prefix in enumerate(prefixes):
if is_win and prefix[0] in 'abcdefghijklmnopqrstuvwxyz':
prefixes[i] = prefix[0].upper() + prefix[1:]
for src_prefix in prefixes:
if filename.startswith(src_prefix):
_, relpath = filename.split(src_prefix, 1)
if src_prefix != os.sep: # sys.prefix == "/"
assert relpath[0] == os.sep
relpath = relpath[1:]
return join(dst_prefix, relpath)
assert False, "Filename %s does not start with any of these prefixes: %s" % \
(filename, prefixes)
def tearDown(self):
if sys.version < "2.6" or hasattr(sys, 'real_prefix') or (hasattr(sys, 'base_prefix') and sys.base_prefix != sys.prefix):
return
os.chdir(self.old_cwd)
shutil.rmtree(self.dir)
shutil.rmtree(site.USER_BASE)
shutil.rmtree(site.USER_SITE)
site.USER_BASE = self.old_base
site.USER_SITE = self.old_site
def test_coverage(coverdir):
trace = support.import_module('trace')
tracer=trace.Trace(ignoredirs=[sys.base_prefix, sys.base_exec_prefix,],
trace=0, count=1)
tracer.run('reload(cmd);test_main()')
r=tracer.results()
print("Writing coverage results...")
r.write_results(show_missing=True, summary=True, coverdir=coverdir)
def test_coverage(coverdir):
trace = support.import_module('trace')
tracer = trace.Trace(ignoredirs=[sys.base_prefix, sys.base_exec_prefix,],
trace=0, count=1)
tracer.run('test_main()')
r = tracer.results()
print('Writing coverage results...')
r.write_results(show_missing=True, summary=True,
coverdir=coverdir)
def test_coverage_ignore(self):
# Ignore all files, nothing should be traced nor printed
libpath = os.path.normpath(os.path.dirname(os.__file__))
# sys.prefix does not work when running from a checkout
tracer = trace.Trace(ignoredirs=[sys.base_prefix, sys.base_exec_prefix,
libpath], trace=0, count=1)
with captured_stdout() as stdout:
self._coverage(tracer)
if os.path.exists(TESTFN):
files = os.listdir(TESTFN)
self.assertEqual(files, ['_importlib.cover']) # Ignore __import__
def change_prefix(filename, dst_prefix):
prefixes = [sys.prefix]
if is_darwin:
prefixes.extend((
os.path.join("/Library/Python", sys.version[:3], "site-packages"),
os.path.join(sys.prefix, "Extras", "lib", "python"),
os.path.join("~", "Library", "Python", sys.version[:3], "site-packages"),
# Python 2.6 no-frameworks
os.path.join("~", ".local", "lib","python", sys.version[:3], "site-packages"),
# System Python 2.7 on OSX Mountain Lion
os.path.join("~", "Library", "Python", sys.version[:3], "lib", "python", "site-packages")))
if hasattr(sys, 'real_prefix'):
prefixes.append(sys.real_prefix)
if hasattr(sys, 'base_prefix'):
prefixes.append(sys.base_prefix)
prefixes = list(map(os.path.expanduser, prefixes))
prefixes = list(map(os.path.abspath, prefixes))
# Check longer prefixes first so we don't split in the middle of a filename
prefixes = sorted(prefixes, key=len, reverse=True)
filename = os.path.abspath(filename)
# On Windows, make sure drive letter is uppercase
if is_win and filename[0] in 'abcdefghijklmnopqrstuvwxyz':
filename = filename[0].upper() + filename[1:]
for i, prefix in enumerate(prefixes):
if is_win and prefix[0] in 'abcdefghijklmnopqrstuvwxyz':
prefixes[i] = prefix[0].upper() + prefix[1:]
for src_prefix in prefixes:
if filename.startswith(src_prefix):
_, relpath = filename.split(src_prefix, 1)
if src_prefix != os.sep: # sys.prefix == "/"
assert relpath[0] == os.sep
relpath = relpath[1:]
return join(dst_prefix, relpath)
assert False, "Filename %s does not start with any of these prefixes: %s" % \
(filename, prefixes)
def setup_detect_python2():
"""
Call this before using the refactoring tools to create them on demand
if needed.
"""
if None in [RTs._rt_py2_detect, RTs._rtp_py2_detect]:
RTs._rt_py2_detect = RefactoringTool(py2_detect_fixers)
RTs._rtp_py2_detect = RefactoringTool(py2_detect_fixers,
{'print_function': True})
# We need to find a prefix for the standard library, as we don't want to
# process any files there (they will already be Python 3).
#
# The following method is used by Sanjay Vinip in uprefix. This fails for
# ``conda`` environments:
# # In a non-pythonv virtualenv, sys.real_prefix points to the installed Python.
# # In a pythonv venv, sys.base_prefix points to the installed Python.
# # Outside a virtual environment, sys.prefix points to the installed Python.
# if hasattr(sys, 'real_prefix'):
# _syslibprefix = sys.real_prefix
# else:
# _syslibprefix = getattr(sys, 'base_prefix', sys.prefix)
# Instead, we use the portion of the path common to both the stdlib modules
# ``math`` and ``urllib``.
def test_is_inside_virtual_env(self):
"""
Check `utils.is_inside_virtual_env()` against various sets of sys prefix paths.
"""
system = mock.sentinel.system
virtual = mock.sentinel.virtual
# These are the sets of sys module attributes that should be present or absent
# with various versions of Python and virtualenv / venv.
test_cases = {
'py2_base': dict(prefix=system),
# Python 3 (as of 3.3 / PEP 405) adds a sys.base_prefix attribute
'py3_base': dict(base_prefix=system, prefix=system),
'py3_venv': dict(base_prefix=system, prefix=virtual),
# virtualenv saves sys.real_prefix, and changes the others
'py2_virtualenv': dict(real_prefix=system, prefix=virtual),
'py3_virtualenv': dict(real_prefix=system, prefix=virtual, base_prefix=virtual),
}
for (label, sys_attrs) in test_cases.items():
with self.subTest(label=label):
# Note: The spec=[] is important so that absent sys_attrs raise AttributeError
# instead of returning mocks.
with mock.patch('django_develop.utils.sys', spec=[], **sys_attrs):
expected = sys_attrs['prefix'] is virtual
self.assertEqual(utils.is_inside_virtual_env(), expected)
def is_inside_virtual_env():
"""
Detect whether a Python virtual environment is active.
This detects environments created using virtualenv, or using Python's built-in venv (PEP 405).
If true, `sys.prefix` should be the virtual environment's root.
This implementation only looks at the `sys` module,
so environment variables like VIRTUAL_ENV do not affect it.
:rtype: bool
"""
is_virtualenv = hasattr(sys, 'real_prefix')
is_venv = hasattr(sys, 'base_prefix') and sys.prefix != sys.base_prefix
return is_virtualenv or is_venv
def setup_detect_python2():
"""
Call this before using the refactoring tools to create them on demand
if needed.
"""
if None in [RTs._rt_py2_detect, RTs._rtp_py2_detect]:
RTs._rt_py2_detect = RefactoringTool(py2_detect_fixers)
RTs._rtp_py2_detect = RefactoringTool(py2_detect_fixers,
{'print_function': True})
# We need to find a prefix for the standard library, as we don't want to
# process any files there (they will already be Python 3).
#
# The following method is used by Sanjay Vinip in uprefix. This fails for
# ``conda`` environments:
# # In a non-pythonv virtualenv, sys.real_prefix points to the installed Python.
# # In a pythonv venv, sys.base_prefix points to the installed Python.
# # Outside a virtual environment, sys.prefix points to the installed Python.
# if hasattr(sys, 'real_prefix'):
# _syslibprefix = sys.real_prefix
# else:
# _syslibprefix = getattr(sys, 'base_prefix', sys.prefix)
# Instead, we use the portion of the path common to both the stdlib modules
# ``math`` and ``urllib``.
def setup_detect_python2():
"""
Call this before using the refactoring tools to create them on demand
if needed.
"""
if None in [RTs._rt_py2_detect, RTs._rtp_py2_detect]:
RTs._rt_py2_detect = RefactoringTool(py2_detect_fixers)
RTs._rtp_py2_detect = RefactoringTool(py2_detect_fixers,
{'print_function': True})
# We need to find a prefix for the standard library, as we don't want to
# process any files there (they will already be Python 3).
#
# The following method is used by Sanjay Vinip in uprefix. This fails for
# ``conda`` environments:
# # In a non-pythonv virtualenv, sys.real_prefix points to the installed Python.
# # In a pythonv venv, sys.base_prefix points to the installed Python.
# # Outside a virtual environment, sys.prefix points to the installed Python.
# if hasattr(sys, 'real_prefix'):
# _syslibprefix = sys.real_prefix
# else:
# _syslibprefix = getattr(sys, 'base_prefix', sys.prefix)
# Instead, we use the portion of the path common to both the stdlib modules
# ``math`` and ``urllib``.
