"""API for Vox, the Python virtual environment manager for xonsh.""" import os import venv import shutil import builtins import collections.abc from xonsh.platform import ON_POSIX, ON_WINDOWS, scandir VirtualEnvironment = collections.namedtuple('VirtualEnvironment', ['env', 'bin']) class EnvironmentInUse(Exception): pass class NoEnvironmentActive(Exception): pass class Vox(collections.abc.Mapping): """API access to Vox and virtual environments, in a dict-like format. Makes use of the VirtualEnvironment namedtuple: 1. ``env``: The full path to the environment 2. ``bin``: The full path to the bin/Scripts directory of the environment """ def __init__(self): if not builtins.__xonsh_env__.get('VIRTUALENV_HOME'): home_path = os.path.expanduser('~') self.venvdir = os.path.join(home_path, '.virtualenvs') builtins.__xonsh_env__['VIRTUALENV_HOME'] = self.venvdir else: self.venvdir = builtins.__xonsh_env__['VIRTUALENV_HOME'] def create(self, name, *, system_site_packages=False, symlinks=False, with_pip=True): """Create a virtual environment in $VIRTUALENV_HOME with python3's ``venv``. Parameters ---------- name : str Virtual environment name system_site_packages : bool If True, the system (global) site-packages dir is available to created environments. symlinks : bool If True, attempt to symlink rather than copy files into virtual environment. with_pip : bool If True, ensure pip is installed in the virtual environment. (Default is True) """ # NOTE: clear=True is the same as delete then create. # NOTE: upgrade=True is its own method env_path = os.path.join(self.venvdir, name) venv.create(env_path, system_site_packages=system_site_packages, symlinks=symlinks, with_pip=with_pip) def upgrade(self, name, *, symlinks=False, with_pip=True): """Create a virtual environment in $VIRTUALENV_HOME with python3's ``venv``. WARNING: If a virtual environment was created with symlinks or without PIP, you must specify these options again on upgrade. Parameters ---------- name : str Virtual environment name symlinks : bool If True, attempt to symlink rather than copy files into virtual environment. with_pip : bool If True, ensure pip is installed in the virtual environment. """ # venv doesn't reload this, so we have to do it ourselves. # Is there a bug for this in Python? There should be. env_path, bin_path = self[name] cfgfile = os.path.join(env_path, 'pyvenv.cfg') cfgops = {} with open(cfgfile) as cfgfile: for l in cfgfile: l = l.strip() if '=' not in l: continue k, v = l.split('=', 1) cfgops[k.strip()] = v.strip() flags = { 'system_site_packages': cfgops['include-system-site-packages'] == 'true', 'symlinks': symlinks, 'with_pip': with_pip, } # END things we shouldn't be doing. # Ok, do what we came here to do. venv.create(env_path, upgrade=True, **flags) @staticmethod def _binname(): if ON_WINDOWS: return 'Scripts' elif ON_POSIX: return 'bin' else: raise OSError('This OS is not supported.') def __getitem__(self, name): """Get information about a virtual environment. Parameters ---------- name : str or Ellipsis Virtual environment name or absolute path. If ... is given, return the current one (throws a KeyError if there isn't one). """ if name is ...: env_path = builtins.__xonsh_env__['VIRTUAL_ENV'] elif os.path.isabs(name): env_path = name else: env_path = os.path.join(self.venvdir, name) bin_dir = self._binname() bin_path = os.path.join(env_path, bin_dir) # Actually check if this is an actual venv or just a organizational directory # eg, if 'spam/eggs' is a venv, reject 'spam' if not os.path.exists(bin_path): raise KeyError() return VirtualEnvironment(env_path, bin_path) def __iter__(self): """List available virtual environments found in $VIRTUALENV_HOME. """ # FIXME: Handle subdirs--this won't discover eg ``spam/eggs`` for x in scandir(self.venvdir): if x.is_dir(): yield x.name def __len__(self): """Counts known virtual environments, using the same rules as iter(). """ l = 0 for _ in self: l += 1 return l def active(self): """Get the name of the active virtual environment. You can use this as a key to get further information. Returns None if no environment is active. """ if 'VIRTUAL_ENV' not in builtins.__xonsh_env__: return env_path = builtins.__xonsh_env__['VIRTUAL_ENV'] if env_path.startswith(self.venvdir): name = env_path[len(self.venvdir):] if name[0] == '/': name = name[1:] return name else: return env_path def activate(self, name): """ Activate a virtual environment. Parameters ---------- name : str Virtual environment name or absolute path. """ env = builtins.__xonsh_env__ env_path, bin_path = self[name] if 'VIRTUAL_ENV' in env: self.deactivate() type(self).oldvars = {'PATH': env['PATH']} env['PATH'].insert(0, bin_path) env['VIRTUAL_ENV'] = env_path if 'PYTHONHOME' in env: type(self).oldvars['PYTHONHOME'] = env.pop('PYTHONHOME') def deactivate(self): """ Deactive the active virtual environment. Returns the name of it. """ env = builtins.__xonsh_env__ if 'VIRTUAL_ENV' not in env: raise NoEnvironmentActive('No environment currently active.') env_path, bin_path = self[...] env_name = self.active() if hasattr(type(self), 'oldvars'): for k, v in type(self).oldvars.items(): env[k] = v del type(self).oldvars env.pop('VIRTUAL_ENV') return env_name def __delitem__(self, name): """ Permanently deletes a virtual environment. Parameters ---------- name : str Virtual environment name or absolute path. """ env_path = self[name].env try: if self[...].env == env_path: raise EnvironmentInUse('The "%s" environment is currently active.' % name) except KeyError: # No current venv, ... fails pass shutil.rmtree(env_path)