""" Virtual environment (venv) package for Python. Based on PEP 405. Copyright (C) 2011-2014 Vinay Sajip. Licensed to the PSF under a contributor agreement. """ import logging import os import shutil import subprocess import sys import sysconfig import types CORE_VENV_DEPS = ('pip',) logger = logging.getLogger(__name__) class EnvBuilder: """ This class exists to allow virtual environment creation to be customized. The constructor parameters determine the builder's behaviour when called upon to create a virtual environment. By default, the builder makes the system (global) site-packages dir *un*available to the created environment. If invoked using the Python -m option, the default is to use copying on Windows platforms but symlinks elsewhere. If instantiated some other way, the default is to *not* use symlinks. :param system_site_packages: If True, the system (global) site-packages dir is available to created environments. :param clear: If True, delete the contents of the environment directory if it already exists, before environment creation. :param symlinks: If True, attempt to symlink rather than copy files into virtual environment. :param upgrade: If True, upgrade an existing virtual environment. :param with_pip: If True, ensure pip is installed in the virtual environment :param prompt: Alternative terminal prefix for the environment. :param upgrade_deps: Update the base venv modules to the latest on PyPI :param scm_ignore_files: Create ignore files for the SCMs specified by the iterable. """ def __init__(self, system_site_packages=False, clear=False, symlinks=False, upgrade=False, with_pip=False, prompt=None, upgrade_deps=False, *, scm_ignore_files=frozenset()): self.system_site_packages = system_site_packages self.clear = clear self.symlinks = symlinks self.upgrade = upgrade self.with_pip = with_pip self.orig_prompt = prompt if prompt == '.': # see bpo-38901 prompt = os.path.basename(os.getcwd()) self.prompt = prompt self.upgrade_deps = upgrade_deps self.scm_ignore_files = frozenset(map(str.lower, scm_ignore_files)) def create(self, env_dir): """ Create a virtual environment in a directory. :param env_dir: The target directory to create an environment in. """ env_dir = os.path.abspath(env_dir) context = self.ensure_directories(env_dir) for scm in self.scm_ignore_files: getattr(self, f"create_{scm}_ignore_file")(context) # See issue 24875. We need system_site_packages to be False # until after pip is installed. true_system_site_packages = self.system_site_packages self.system_site_packages = False self.create_configuration(context) self.setup_python(context) if self.with_pip: self._setup_pip(context) if not self.upgrade: self.setup_scripts(context) self.post_setup(context) if true_system_site_packages: # We had set it to False before, now # restore it and rewrite the configuration self.system_site_packages = True self.create_configuration(context) if self.upgrade_deps: self.upgrade_dependencies(context) def clear_directory(self, path): for fn in os.listdir(path): fn = os.path.join(path, fn) if os.path.islink(fn) or os.path.isfile(fn): os.remove(fn) elif os.path.isdir(fn): shutil.rmtree(fn) def _venv_path(self, env_dir, name): vars = { 'base': env_dir, 'platbase': env_dir, 'installed_base': env_dir, 'installed_platbase': env_dir, } return sysconfig.get_path(name, scheme='venv', vars=vars) @classmethod def _same_path(cls, path1, path2): """Check whether two paths appear the same. Whether they refer to the same file is irrelevant; we're testing for whether a human reader would look at the path string and easily tell that they're the same file. """ if sys.platform == 'win32': if os.path.normcase(path1) == os.path.normcase(path2): return True # gh-90329: Don't display a warning for short/long names import _winapi try: path1 = _winapi.GetLongPathName(os.fsdecode(path1)) except OSError: pass try: path2 = _winapi.GetLongPathName(os.fsdecode(path2)) except OSError: pass if os.path.normcase(path1) == os.path.normcase(path2): return True return False else: return path1 == path2 def ensure_directories(self, env_dir): """ Create the directories for the environment. Returns a context object which holds paths in the environment, for use by subsequent logic. """ def create_if_needed(d): if not os.path.exists(d): os.makedirs(d) elif os.path.islink(d) or os.path.isfile(d): raise ValueError('Unable to create directory %r' % d) if os.pathsep in os.fspath(env_dir): raise ValueError(f'Refusing to create a venv in {env_dir} because ' f'it contains the PATH separator {os.pathsep}.') if os.path.exists(env_dir) and self.clear: self.clear_directory(env_dir) context = types.SimpleNamespace() context.env_dir = env_dir context.env_name = os.path.split(env_dir)[1] context.prompt = self.prompt if self.prompt is not None else context.env_name create_if_needed(env_dir) executable = sys._base_executable if not executable: # see gh-96861 raise ValueError('Unable to determine path to the running ' 'Python interpreter. Provide an explicit path or ' 'check that your PATH environment variable is ' 'correctly set.') dirname, exename = os.path.split(os.path.abspath(executable)) if sys.platform == 'win32': # Always create the simplest name in the venv. It will either be a # link back to executable, or a copy of the appropriate launcher _d = '_d' if os.path.splitext(exename)[0].endswith('_d') else '' exename = f'python{_d}.exe' context.executable = executable context.python_dir = dirname context.python_exe = exename binpath = self._venv_path(env_dir, 'scripts') incpath = self._venv_path(env_dir, 'include') libpath = self._venv_path(env_dir, 'purelib') context.inc_path = incpath create_if_needed(incpath) context.lib_path = libpath create_if_needed(libpath) # Issue 21197: create lib64 as a symlink to lib on 64-bit non-OS X POSIX if ((sys.maxsize > 2**32) and (os.name == 'posix') and (sys.platform != 'darwin')): link_path = os.path.join(env_dir, 'lib64') if not os.path.exists(link_path): # Issue #21643 os.symlink('lib', link_path) context.bin_path = binpath context.bin_name = os.path.relpath(binpath, env_dir) context.env_exe = os.path.join(binpath, exename) create_if_needed(binpath) # Assign and update the command to use when launching the newly created # environment, in case it isn't simply the executable script (e.g. bpo-45337) context.env_exec_cmd = context.env_exe if sys.platform == 'win32': # bpo-45337: Fix up env_exec_cmd to account for file system redirections. # Some redirects only apply to CreateFile and not CreateProcess real_env_exe = os.path.realpath(context.env_exe) if not self._same_path(real_env_exe, context.env_exe): logger.warning('Actual environment location may have moved due to ' 'redirects, links or junctions.\n' ' Requested location: "%s"\n' ' Actual location: "%s"', context.env_exe, real_env_exe) context.env_exec_cmd = real_env_exe return context def create_configuration(self, context): """ Create a configuration file indicating where the environment's Python was copied from, and whether the system site-packages should be made available in the environment. :param context: The information for the environment creation request being processed. """ context.cfg_path = path = os.path.join(context.env_dir, 'pyvenv.cfg') with open(path, 'w', encoding='utf-8') as f: f.write('home = %s\n' % context.python_dir) if self.system_site_packages: incl = 'true' else: incl = 'false' f.write('include-system-site-packages = %s\n' % incl) f.write('version = %d.%d.%d\n' % sys.version_info[:3]) if self.prompt is not None: f.write(f'prompt = {self.prompt!r}\n') f.write('executable = %s\n' % os.path.realpath(sys.executable)) args = [] nt = os.name == 'nt' if nt and self.symlinks: args.append('--symlinks') if not nt and not self.symlinks: args.append('--copies') if not self.with_pip: args.append('--without-pip') if self.system_site_packages: args.append('--system-site-packages') if self.clear: args.append('--clear') if self.upgrade: args.append('--upgrade') if self.upgrade_deps: args.append('--upgrade-deps') if self.orig_prompt is not None: args.append(f'--prompt="{self.orig_prompt}"') if not self.scm_ignore_files: args.append('--without-scm-ignore-files') args.append(context.env_dir) args = ' '.join(args) f.write(f'command = {sys.executable} -m venv {args}\n') def symlink_or_copy(self, src, dst, relative_symlinks_ok=False): """ Try symlinking a file, and if that fails, fall back to copying. (Unused on Windows, because we can't just copy a failed symlink file: we switch to a different set of files instead.) """ assert os.name != 'nt' force_copy = not self.symlinks if not force_copy: try: if not os.path.islink(dst): # can't link to itself! if relative_symlinks_ok: assert os.path.dirname(src) == os.path.dirname(dst) os.symlink(os.path.basename(src), dst) else: os.symlink(src, dst) except Exception: # may need to use a more specific exception logger.warning('Unable to symlink %r to %r', src, dst) force_copy = True if force_copy: shutil.copyfile(src, dst) def create_git_ignore_file(self, context): """ Create a .gitignore file in the environment directory. The contents of the file cause the entire environment directory to be ignored by git. """ gitignore_path = os.path.join(context.env_dir, '.gitignore') with open(gitignore_path, 'w', encoding='utf-8') as file: file.write('# Created by venv; ' 'see https://docs.python.org/3/library/venv.html\n') file.write('*\n') if os.name != 'nt': def setup_python(self, context): """ Set up a Python executable in the environment. :param context: The information for the environment creation request being processed. """ binpath = context.bin_path path = context.env_exe copier = self.symlink_or_copy dirname = context.python_dir copier(context.executable, path) if not os.path.islink(path): os.chmod(path, 0o755) suffixes = ['python', 'python3', f'python3.{sys.version_info[1]}'] if sys.version_info[:2] == (3, 14): suffixes.append('𝜋thon') for suffix in suffixes: path = os.path.join(binpath, suffix) if not os.path.exists(path): # Issue 18807: make copies if # symlinks are not wanted copier(context.env_exe, path, relative_symlinks_ok=True) if not os.path.islink(path): os.chmod(path, 0o755) else: def setup_python(self, context): """ Set up a Python executable in the environment. :param context: The information for the environment creation request being processed. """ binpath = context.bin_path dirname = context.python_dir exename = os.path.basename(context.env_exe) exe_stem = os.path.splitext(exename)[0] exe_d = '_d' if os.path.normcase(exe_stem).endswith('_d') else '' if sysconfig.is_python_build(): scripts = dirname else: scripts = os.path.join(os.path.dirname(__file__), 'scripts', 'nt') if not sysconfig.get_config_var("Py_GIL_DISABLED"): python_exe = os.path.join(dirname, f'python{exe_d}.exe') pythonw_exe = os.path.join(dirname, f'pythonw{exe_d}.exe') link_sources = { 'python.exe': python_exe, f'python{exe_d}.exe': python_exe, 'pythonw.exe': pythonw_exe, f'pythonw{exe_d}.exe': pythonw_exe, } python_exe = os.path.join(scripts, f'venvlauncher{exe_d}.exe') pythonw_exe = os.path.join(scripts, f'venvwlauncher{exe_d}.exe') copy_sources = { 'python.exe': python_exe, f'python{exe_d}.exe': python_exe, 'pythonw.exe': pythonw_exe, f'pythonw{exe_d}.exe': pythonw_exe, } else: exe_t = f'3.{sys.version_info[1]}t' python_exe = os.path.join(dirname, f'python{exe_t}{exe_d}.exe') pythonw_exe = os.path.join(dirname, f'pythonw{exe_t}{exe_d}.exe') link_sources = { 'python.exe': python_exe, f'python{exe_d}.exe': python_exe, f'python{exe_t}.exe': python_exe, f'python{exe_t}{exe_d}.exe': python_exe, 'pythonw.exe': pythonw_exe, f'pythonw{exe_d}.exe': pythonw_exe, f'pythonw{exe_t}.exe': pythonw_exe, f'pythonw{exe_t}{exe_d}.exe': pythonw_exe, } python_exe = os.path.join(scripts, f'venvlaunchert{exe_d}.exe') pythonw_exe = os.path.join(scripts, f'venvwlaunchert{exe_d}.exe') copy_sources = { 'python.exe': python_exe, f'python{exe_d}.exe': python_exe, f'python{exe_t}.exe': python_exe, f'python{exe_t}{exe_d}.exe': python_exe, 'pythonw.exe': pythonw_exe, f'pythonw{exe_d}.exe': pythonw_exe, f'pythonw{exe_t}.exe': pythonw_exe, f'pythonw{exe_t}{exe_d}.exe': pythonw_exe, } do_copies = True if self.symlinks: do_copies = False # For symlinking, we need all the DLLs to be available alongside # the executables. link_sources.update({ f: os.path.join(dirname, f) for f in os.listdir(dirname) if os.path.normcase(f).startswith(('python', 'vcruntime')) and os.path.normcase(os.path.splitext(f)[1]) == '.dll' }) to_unlink = [] for dest, src in link_sources.items(): dest = os.path.join(binpath, dest) try: os.symlink(src, dest) to_unlink.append(dest) except OSError: logger.warning('Unable to symlink %r to %r', src, dest) do_copies = True for f in to_unlink: try: os.unlink(f) except OSError: logger.warning('Failed to clean up symlink %r', f) logger.warning('Retrying with copies') break if do_copies: for dest, src in copy_sources.items(): dest = os.path.join(binpath, dest) try: shutil.copy2(src, dest) except OSError: logger.warning('Unable to copy %r to %r', src, dest) if sysconfig.is_python_build(): # copy init.tcl for root, dirs, files in os.walk(context.python_dir): if 'init.tcl' in files: tcldir = os.path.basename(root) tcldir = os.path.join(context.env_dir, 'Lib', tcldir) if not os.path.exists(tcldir): os.makedirs(tcldir) src = os.path.join(root, 'init.tcl') dst = os.path.join(tcldir, 'init.tcl') shutil.copyfile(src, dst) break def _call_new_python(self, context, *py_args, **kwargs): """Executes the newly created Python using safe-ish options""" # gh-98251: We do not want to just use '-I' because that masks # legitimate user preferences (such as not writing bytecode). All we # really need is to ensure that the path variables do not overrule # normal venv handling. args = [context.env_exec_cmd, *py_args] kwargs['env'] = env = os.environ.copy() env['VIRTUAL_ENV'] = context.env_dir env.pop('PYTHONHOME', None) env.pop('PYTHONPATH', None) kwargs['cwd'] = context.env_dir kwargs['executable'] = context.env_exec_cmd subprocess.check_output(args, **kwargs) def _setup_pip(self, context): """Installs or upgrades pip in a virtual environment""" self._call_new_python(context, '-m', 'ensurepip', '--upgrade', '--default-pip', stderr=subprocess.STDOUT) def setup_scripts(self, context): """ Set up scripts into the created environment from a directory. This method installs the default scripts into the environment being created. You can prevent the default installation by overriding this method if you really need to, or if you need to specify a different location for the scripts to install. By default, the 'scripts' directory in the venv package is used as the source of scripts to install. """ path = os.path.abspath(os.path.dirname(__file__)) path = os.path.join(path, 'scripts') self.install_scripts(context, path) def post_setup(self, context): """ Hook for post-setup modification of the venv. Subclasses may install additional packages or scripts here, add activation shell scripts, etc. :param context: The information for the environment creation request being processed. """ pass def replace_variables(self, text, context): """ Replace variable placeholders in script text with context-specific variables. Return the text passed in , but with variables replaced. :param text: The text in which to replace placeholder variables. :param context: The information for the environment creation request being processed. """ text = text.replace('__VENV_DIR__', context.env_dir) text = text.replace('__VENV_NAME__', context.env_name) text = text.replace('__VENV_PROMPT__', context.prompt) text = text.replace('__VENV_BIN_NAME__', context.bin_name) text = text.replace('__VENV_PYTHON__', context.env_exe) return text def install_scripts(self, context, path): """ Install scripts into the created environment from a directory. :param context: The information for the environment creation request being processed. :param path: Absolute pathname of a directory containing script. Scripts in the 'common' subdirectory of this directory, and those in the directory named for the platform being run on, are installed in the created environment. Placeholder variables are replaced with environment- specific values. """ binpath = context.bin_path plen = len(path) if os.name == 'nt': def skip_file(f): f = os.path.normcase(f) return (f.startswith(('python', 'venv')) and f.endswith(('.exe', '.pdb'))) else: def skip_file(f): return False for root, dirs, files in os.walk(path): if root == path: # at top-level, remove irrelevant dirs for d in dirs[:]: if d not in ('common', os.name): dirs.remove(d) continue # ignore files in top level for f in files: if skip_file(f): continue srcfile = os.path.join(root, f) suffix = root[plen:].split(os.sep)[2:] if not suffix: dstdir = binpath else: dstdir = os.path.join(binpath, *suffix) if not os.path.exists(dstdir): os.makedirs(dstdir) dstfile = os.path.join(dstdir, f) if os.name == 'nt' and srcfile.endswith(('.exe', '.pdb')): shutil.copy2(srcfile, dstfile) continue with open(srcfile, 'rb') as f: data = f.read() try: new_data = ( self.replace_variables(data.decode('utf-8'), context) .encode('utf-8') ) except UnicodeError as e: logger.warning('unable to copy script %r, ' 'may be binary: %s', srcfile, e) continue if new_data == data: shutil.copy2(srcfile, dstfile) else: with open(dstfile, 'wb') as f: f.write(new_data) shutil.copymode(srcfile, dstfile) def upgrade_dependencies(self, context): logger.debug( f'Upgrading {CORE_VENV_DEPS} packages in {context.bin_path}' ) self._call_new_python(context, '-m', 'pip', 'install', '--upgrade', *CORE_VENV_DEPS) def create(env_dir, system_site_packages=False, clear=False, symlinks=False, with_pip=False, prompt=None, upgrade_deps=False, *, scm_ignore_files=frozenset()): """Create a virtual environment in a directory.""" builder = EnvBuilder(system_site_packages=system_site_packages, clear=clear, symlinks=symlinks, with_pip=with_pip, prompt=prompt, upgrade_deps=upgrade_deps, scm_ignore_files=scm_ignore_files) builder.create(env_dir) def main(args=None): import argparse parser = argparse.ArgumentParser(description='Creates virtual Python ' 'environments in one or ' 'more target ' 'directories.', epilog='Once an environment has been ' 'created, you may wish to ' 'activate it, e.g. by ' 'sourcing an activate script ' 'in its bin directory.') parser.add_argument('dirs', metavar='ENV_DIR', nargs='+', help='A directory to create the environment in.') parser.add_argument('--system-site-packages', default=False, action='store_true', dest='system_site', help='Give the virtual environment access to the ' 'system site-packages dir.') if os.name == 'nt': use_symlinks = False else: use_symlinks = True group = parser.add_mutually_exclusive_group() group.add_argument('--symlinks', default=use_symlinks, action='store_true', dest='symlinks', help='Try to use symlinks rather than copies, ' 'when symlinks are not the default for ' 'the platform.') group.add_argument('--copies', default=not use_symlinks, action='store_false', dest='symlinks', help='Try to use copies rather than symlinks, ' 'even when symlinks are the default for ' 'the platform.') parser.add_argument('--clear', default=False, action='store_true', dest='clear', help='Delete the contents of the ' 'environment directory if it ' 'already exists, before ' 'environment creation.') parser.add_argument('--upgrade', default=False, action='store_true', dest='upgrade', help='Upgrade the environment ' 'directory to use this version ' 'of Python, assuming Python ' 'has been upgraded in-place.') parser.add_argument('--without-pip', dest='with_pip', default=True, action='store_false', help='Skips installing or upgrading pip in the ' 'virtual environment (pip is bootstrapped ' 'by default)') parser.add_argument('--prompt', help='Provides an alternative prompt prefix for ' 'this environment.') parser.add_argument('--upgrade-deps', default=False, action='store_true', dest='upgrade_deps', help=f'Upgrade core dependencies ({", ".join(CORE_VENV_DEPS)}) ' 'to the latest version in PyPI') parser.add_argument('--without-scm-ignore-files', dest='scm_ignore_files', action='store_const', const=frozenset(), default=frozenset(['git']), help='Skips adding SCM ignore files to the environment ' 'directory (Git is supported by default).') options = parser.parse_args(args) if options.upgrade and options.clear: raise ValueError('you cannot supply --upgrade and --clear together.') builder = EnvBuilder(system_site_packages=options.system_site, clear=options.clear, symlinks=options.symlinks, upgrade=options.upgrade, with_pip=options.with_pip, prompt=options.prompt, upgrade_deps=options.upgrade_deps, scm_ignore_files=options.scm_ignore_files) for d in options.dirs: builder.create(d) if __name__ == '__main__': rc = 1 try: main() rc = 0 except Exception as e: print('Error: %s' % e, file=sys.stderr) sys.exit(rc)