Python sys.prefix() Examples

def _compute_site_packages():
        def _normalized_path(path):
            return os.path.normcase(os.path.abspath(path))

        paths = set()
        real_prefix = getattr(sys, 'real_prefix', None)
        for prefix in filter(None, (real_prefix, sys.prefix)):
            path = sysconfig.get_python_lib(prefix=prefix)
            path = _normalized_path(path)
            paths.add(path)

        # Handle Debian's derivatives /usr/local.
        if os.path.isfile("/etc/debian_version"):
            for prefix in filter(None, (real_prefix, sys.prefix)):
                libpython = os.path.join(prefix, "local", "lib",
                                         "python" + sysconfig.get_python_version(),
                                         "dist-packages")
                paths.add(libpython)
        return paths 

def save(self, pypi_version, current_time):
        # Check to make sure that we own the directory
        if not check_path_owner(os.path.dirname(self.statefile_path)):
            return

        # Now that we've ensured the directory is owned by this user, we'll go
        # ahead and make sure that all our directories are created.
        ensure_dir(os.path.dirname(self.statefile_path))

        # Attempt to write out our version check file
        with lockfile.LockFile(self.statefile_path):
            if os.path.exists(self.statefile_path):
                with open(self.statefile_path) as statefile:
                    state = json.load(statefile)
            else:
                state = {}

            state[sys.prefix] = {
                "last_check": current_time.strftime(SELFCHECK_DATE_FMT),
                "pypi_version": pypi_version,
            }

            with open(self.statefile_path, "w") as statefile:
                json.dump(state, statefile, sort_keys=True,
                          separators=(",", ":")) 

def get_resources_dests(resources_root, rules):
    """Find destinations for resources files"""

    def get_rel_path(base, path):
        # normalizes and returns a lstripped-/-separated path
        base = base.replace(os.path.sep, '/')
        path = path.replace(os.path.sep, '/')
        assert path.startswith(base)
        return path[len(base):].lstrip('/')


    destinations = {}
    for base, suffix, dest in rules:
        prefix = os.path.join(resources_root, base)
        for abs_base in iglob(prefix):
            abs_glob = os.path.join(abs_base, suffix)
            for abs_path in iglob(abs_glob):
                resource_file = get_rel_path(resources_root, abs_path)
                if dest is None:  # remove the entry if it was here
                    destinations.pop(resource_file, None)
                else:
                    rel_path = get_rel_path(abs_base, abs_path)
                    rel_dest = dest.replace(os.path.sep, '/').rstrip('/')
                    destinations[resource_file] = rel_dest + '/' + rel_path
    return destinations 

def ETA(self):
        if self.done:
            prefix = 'Done'
            t = self.elapsed
            #import pdb; pdb.set_trace()
        else:
            prefix = 'ETA '
            if self.max is None:
                t = -1
            elif self.elapsed == 0 or (self.cur == self.min):
                t = 0
            else:
                #import pdb; pdb.set_trace()
                t = float(self.max - self.min)
                t /= self.cur - self.min
                t = (t - 1) * self.elapsed
        return '%s: %s' % (prefix, self.format_duration(t)) 

def _build_import_library_amd64():
    out_exists, out_file = _check_for_import_lib()
    if out_exists:
        log.debug('Skip building import library: "%s" exists', out_file)
        return

    # get the runtime dll for which we are building import library
    dll_file = find_python_dll()
    log.info('Building import library (arch=AMD64): "%s" (from %s)' %
             (out_file, dll_file))

    # generate symbol list from this library
    def_name = "python%d%d.def" % tuple(sys.version_info[:2])
    def_file = os.path.join(sys.prefix, 'libs', def_name)
    generate_def(dll_file, def_file)

    # generate import library from this symbol list
    cmd = ['dlltool', '-d', def_file, '-l', out_file]
    subprocess.Popen(cmd) 

def save(self, pypi_version, current_time):
        # Check to make sure that we own the directory
        if not check_path_owner(os.path.dirname(self.statefile_path)):
            return

        # Now that we've ensured the directory is owned by this user, we'll go
        # ahead and make sure that all our directories are created.
        ensure_dir(os.path.dirname(self.statefile_path))

        # Attempt to write out our version check file
        with lockfile.LockFile(self.statefile_path):
            if os.path.exists(self.statefile_path):
                with open(self.statefile_path) as statefile:
                    state = json.load(statefile)
            else:
                state = {}

            state[sys.prefix] = {
                "last_check": current_time.strftime(SELFCHECK_DATE_FMT),
                "pypi_version": pypi_version,
            }

            with open(self.statefile_path, "w") as statefile:
                json.dump(state, statefile, sort_keys=True,
                          separators=(",", ":")) 

def find_dll(dll_name):

    arch = {'AMD64' : 'amd64',
            'Intel' : 'x86'}[get_build_architecture()]

    def _find_dll_in_winsxs(dll_name):
        # Walk through the WinSxS directory to find the dll.
        winsxs_path = os.path.join(os.environ.get('WINDIR', r'C:\WINDOWS'),
                                   'winsxs')
        if not os.path.exists(winsxs_path):
            return None
        for root, dirs, files in os.walk(winsxs_path):
            if dll_name in files and arch in root:
                return os.path.join(root, dll_name)
        return None

    def _find_dll_in_path(dll_name):
        # First, look in the Python directory, then scan PATH for
        # the given dll name.
        for path in [sys.prefix] + os.environ['PATH'].split(';'):
            filepath = os.path.join(path, dll_name)
            if os.path.exists(filepath):
                return os.path.abspath(filepath)

    return _find_dll_in_winsxs(dll_name) or _find_dll_in_path(dll_name) 

def write_exports(exports, stream):
    if sys.version_info[0] >= 3:
        # needs to be a text stream
        stream = codecs.getwriter('utf-8')(stream)
    cp = configparser.ConfigParser()
    for k, v in exports.items():
        # TODO check k, v for valid values
        cp.add_section(k)
        for entry in v.values():
            if entry.suffix is None:
                s = entry.prefix
            else:
                s = '%s:%s' % (entry.prefix, entry.suffix)
            if entry.flags:
                s = '%s [%s]' % (s, ', '.join(entry.flags))
            cp.set(k, entry.name, s)
    cp.write(stream) 

def _find_lib(self, lib_dir, lib, exts):
        assert is_string(lib_dir)
        # under windows first try without 'lib' prefix
        if sys.platform == 'win32':
            lib_prefixes = ['', 'lib']
        else:
            lib_prefixes = ['lib']
        # for each library name, see if we can find a file for it.
        for ext in exts:
            for prefix in lib_prefixes:
                p = self.combine_paths(lib_dir, prefix + lib + ext)
                if p:
                    break
            if p:
                assert len(p) == 1
                # ??? splitext on p[0] would do this for cygwin
                # doesn't seem correct
                if ext == '.dll.a':
                    lib += '.dll'
                if ext == '.lib':
                    lib = prefix + lib
                return lib

        return False 

def get_resources_dests(resources_root, rules):
    """Find destinations for resources files"""

    def get_rel_path(base, path):
        # normalizes and returns a lstripped-/-separated path
        base = base.replace(os.path.sep, '/')
        path = path.replace(os.path.sep, '/')
        assert path.startswith(base)
        return path[len(base):].lstrip('/')


    destinations = {}
    for base, suffix, dest in rules:
        prefix = os.path.join(resources_root, base)
        for abs_base in iglob(prefix):
            abs_glob = os.path.join(abs_base, suffix)
            for abs_path in iglob(abs_glob):
                resource_file = get_rel_path(resources_root, abs_path)
                if dest is None:  # remove the entry if it was here
                    destinations.pop(resource_file, None)
                else:
                    rel_path = get_rel_path(abs_base, abs_path)
                    rel_dest = dest.replace(os.path.sep, '/').rstrip('/')
                    destinations[resource_file] = rel_dest + '/' + rel_path
    return destinations 

def run(self):
        if self.verbose != self.distribution.verbose:
            log.set_verbosity(self.verbose)
        try:
            for spec in self.args:
                self.easy_install(spec, not self.no_deps)
            if self.record:
                outputs = self.outputs
                if self.root:  # strip any package prefix
                    root_len = len(self.root)
                    for counter in range(len(outputs)):
                        outputs[counter] = outputs[counter][root_len:]
                from distutils import file_util

                self.execute(
                    file_util.write_file, (self.record, outputs),
                    "writing list of installed files to '%s'" %
                    self.record
                )
            self.warn_deprecated_options()
        finally:
            log.set_verbosity(self.distribution.verbose) 

def build_and_install(self, setup_script, setup_base):
        args = ['bdist_egg', '--dist-dir']

        dist_dir = tempfile.mkdtemp(
            prefix='egg-dist-tmp-', dir=os.path.dirname(setup_script)
        )
        try:
            self._set_fetcher_options(os.path.dirname(setup_script))
            args.append(dist_dir)

            self.run_setup(setup_script, setup_base, args)
            all_eggs = Environment([dist_dir])
            eggs = []
            for key in all_eggs:
                for dist in all_eggs[key]:
                    eggs.append(self.install_egg(dist.location, setup_base))
            if not eggs and not self.dry_run:
                log.warn("No eggs found in %s (setup script problem?)",
                         dist_dir)
            return eggs
        finally:
            rmtree(dist_dir)
            log.set_verbosity(self.verbose)  # restore our log verbosity 

def _expand(self, *attrs):
        config_vars = self.get_finalized_command('install').config_vars

        if self.prefix:
            # Set default install_dir/scripts from --prefix
            config_vars = config_vars.copy()
            config_vars['base'] = self.prefix
            scheme = self.INSTALL_SCHEMES.get(os.name, self.DEFAULT_SCHEME)
            for attr, val in scheme.items():
                if getattr(self, attr, None) is None:
                    setattr(self, attr, val)

        from distutils.util import subst_vars

        for attr in attrs:
            val = getattr(self, attr)
            if val is not None:
                val = subst_vars(val, config_vars)
                if os.name == 'posix':
                    val = os.path.expanduser(val)
                setattr(self, attr, val) 

def get_install_paths(name):
    """
    Return the (distutils) install paths for the named dist.
    
    A dict with ('purelib', 'platlib', 'headers', 'scripts', 'data') keys.
    """
    paths = {}

    i = get_install_command(name)

    for key in install.SCHEME_KEYS:
        paths[key] = getattr(i, 'install_' + key)

    # pip uses a similar path as an alternative to the system's (read-only)
    # include directory:
    if hasattr(sys, 'real_prefix'):  # virtualenv
        paths['headers'] = os.path.join(sys.prefix,
                                        'include',
                                        'site',
                                        'python' + sys.version[:3],
                                        name)

    return paths 

def testUnrepr(self):
        self.getPage('/repr?key=neg')
        self.assertBody('-1234')

        self.getPage('/repr?key=filename')
        self.assertBody(repr(os.path.join(sys.prefix, 'hello.py')))

        self.getPage('/repr?key=thing1')
        self.assertBody(repr(cherrypy.lib.httputil.response_codes[404]))

        if not getattr(cherrypy.server, 'using_apache', False):
            # The object ID's won't match up when using Apache, since the
            # server and client are running in different processes.
            self.getPage('/repr?key=thing2')
            from cherrypy.tutorial import thing2
            self.assertBody(repr(thing2))

        self.getPage('/repr?key=complex')
        self.assertBody('(3+2j)')

        self.getPage('/repr?key=mul')
        self.assertBody('18')

        self.getPage('/repr?key=stradd')
        self.assertBody(repr('112233')) 

def __init__(self, cache_path=False):
        """
        Create Analex Cache
        """
        # use this dictionary as a local cache,
        # The global db will be updated on destructing object
        # get the database path
        if hasattr(sys, 'frozen'): # only when running in py2exe this exists
            base = sys.prefix
        else: # otherwise this is a regular python script
            base = os.path.dirname(os.path.realpath(__file__))
        if not cache_path:
            file_path = self.DB_PATH
        else:
            file_path = os.path.join(os.path.dirname(cache_path), '.thaalabCache')
        
        self.cache={};
        self.db = Database(file_path)
        if not self.db.exists():
            self.db.create();
            x_ind = WithAIndex(self.db.path, 'a')
            self.db.add_index(x_ind)        
        else:
            self.db.open(); 

def ETA(self):
        if self.done:
            prefix = 'Done'
            t = self.elapsed
            #import pdb; pdb.set_trace()
        else:
            prefix = 'ETA '
            if self.max is None:
                t = -1
            elif self.elapsed == 0 or (self.cur == self.min):
                t = 0
            else:
                #import pdb; pdb.set_trace()
                t = float(self.max - self.min)
                t /= self.cur - self.min
                t = (t - 1) * self.elapsed
        return '%s: %s' % (prefix, self.format_duration(t)) 

def __str__(self):
        """Return annotated source code for the function."""
        if self.filename is None:
            return "cannot show coverage data since co_filename is None"
        lines = []
        lineno = self.firstlineno
        for line in self.source:
            counter = self.sourcelines.get(lineno)
            if counter is None:
                prefix = ' ' * 7
            elif counter == 0:
                if self.blank_rx.match(line):  # pragma: nocover
                    # This is an workaround for an ancient bug I can't
                    # reproduce, perhaps because it was fixed, or perhaps
                    # because I can't remember all the details.
                    prefix = ' ' * 7
                else:
                    prefix = '>' * 6 + ' '
            else:
                prefix = '%5d: ' % counter
            lines.append(prefix + line)
            lineno += 1
        return ''.join(lines) 

def _check_bom(self):
        # Normalize our encoding name
        enc = re.sub('[ -]', '', self.encoding.lower())

        # Look up our encoding in the BOM table.
        bom_info = self._BOM_TABLE.get(enc)

        if bom_info:
            # Read a prefix, to check against the BOM(s)
            bytes = self.stream.read(16)
            self.stream.seek(0)

            # Check for each possible BOM.
            for (bom, new_encoding) in bom_info:
                if bytes.startswith(bom):
                    if new_encoding:
                        self.encoding = new_encoding
                    return len(bom)

        return None 

def find_package(name: str) -> Tuple[Optional[Path], Path]:
    """Finds packages install prefix (or None) and it's containing Folder
    """
    module = name.split(".")[0]
    loader = pkgutil.get_loader(module)
    if name == "__main__" or loader is None:
        package_path = Path.cwd()
    else:
        if hasattr(loader, "get_filename"):
            filename = loader.get_filename(module)  # type: ignore
        else:
            __import__(name)
            filename = sys.modules[name].__file__
        package_path = Path(filename).resolve().parent
        if hasattr(loader, "is_package"):
            is_package = loader.is_package(module)  # type: ignore
            if is_package:
                package_path = Path(package_path).resolve().parent
    sys_prefix = Path(sys.prefix).resolve()
    try:
        package_path.relative_to(sys_prefix)
    except ValueError:
        return None, package_path
    else:
        return sys_prefix, package_path 

def in_venv():
    if hasattr(sys, 'real_prefix'):
        # virtualenv venvs
        result = True
    else:
        # PEP 405 venvs
        result = sys.prefix != getattr(sys, 'base_prefix', sys.prefix)
    return result 

def get_export_entry(specification):
    m = ENTRY_RE.search(specification)
    if not m:
        result = None
        if '[' in specification or ']' in specification:
            raise DistlibException('Invalid specification '
                                   '%r' % specification)
    else:
        d = m.groupdict()
        name = d['name']
        path = d['callable']
        colons = path.count(':')
        if colons == 0:
            prefix, suffix = path, None
        else:
            if colons != 1:
                raise DistlibException('Invalid specification '
                                       '%r' % specification)
            prefix, suffix = path.split(':')
        flags = d['flags']
        if flags is None:
            if '[' in specification or ']' in specification:
                raise DistlibException('Invalid specification '
                                       '%r' % specification)
            flags = []
        else:
            flags = [f.strip() for f in flags.split(',')]
        result = ExportEntry(name, prefix, suffix, flags)
    return result 

def __eq__(self, other):
        if not isinstance(other, ExportEntry):
            result = False
        else:
            result = (self.name == other.name and
                      self.prefix == other.prefix and
                      self.suffix == other.suffix and
                      self.flags == other.flags)
        return result 

def get_config_files(self):
        # the files returned by this method will be parsed in order with the
        # first files listed being overridden by later files in standard
        # ConfigParser fashion
        config_file = os.environ.get('PIP_CONFIG_FILE', False)
        if config_file == os.devnull:
            return []

        # at the base we have any site-wide configuration
        files = list(site_config_files)

        # per-user configuration next
        if not self.isolated:
            if config_file and os.path.exists(config_file):
                files.append(config_file)
            else:
                # This is the legacy config file, we consider it to be a lower
                # priority than the new file location.
                files.append(legacy_config_file)

                # This is the new config file, we consider it to be a higher
                # priority than the legacy file.
                files.append(
                    os.path.join(
                        appdirs.user_config_dir("pip"),
                        config_basename,
                    )
                )

        # finally virtualenv configuration first trumping others
        if running_under_virtualenv():
            venv_config_file = os.path.join(
                sys.prefix,
                config_basename,
            )
            if os.path.exists(venv_config_file):
                files.append(venv_config_file)

        return files 

def __repr__(self):
        return '<ExportEntry %s = %s:%s %s>' % (self.name, self.prefix,
                                                self.suffix, self.flags) 

def value(self):
        return resolve(self.prefix, self.suffix) 

def byte_compile(self, path, optimize=False, force=False, prefix=None):
        dpath = cache_from_source(path, not optimize)
        logger.info('Byte-compiling %s to %s', path, dpath)
        if not self.dry_run:
            if force or self.newer(path, dpath):
                if not prefix:
                    diagpath = None
                else:
                    assert path.startswith(prefix)
                    diagpath = path[len(prefix):]
            py_compile.compile(path, dpath, diagpath, True)     # raise error
        self.record_as_written(dpath)
        return dpath 

def _clean_zip_name(self, name, prefix):
        assert name.startswith(prefix + os.path.sep), (
            "name %r doesn't start with prefix %r" % (name, prefix)
        )
        name = name[len(prefix) + 1:]
        name = name.replace(os.path.sep, '/')
        return name 

def get_ffmpeg_exe():
    """
    Get the ffmpeg executable file. This can be the binary defined by
    the IMAGEIO_FFMPEG_EXE environment variable, the binary distributed
    with imageio-ffmpeg, an ffmpeg binary installed with conda, or the
    system ffmpeg (in that order). A RuntimeError is raised if no valid
    ffmpeg could be found.
    """

    # 1. Try environment variable. - Dont test it: the user is explicit here!
    exe = os.getenv("IMAGEIO_FFMPEG_EXE", None)
    if exe:
        return exe

    plat = get_platform()

    # 2. Try from here
    bin_dir = resource_filename("imageio_ffmpeg", "binaries")
    exe = os.path.join(bin_dir, FNAME_PER_PLATFORM.get(plat, ""))
    if exe and os.path.isfile(exe) and _is_valid_exe(exe):
        return exe

    # 3. Try binary from conda package
    # (installed e.g. via `conda install ffmpeg -c conda-forge`)
    if plat.startswith("win"):
        exe = os.path.join(sys.prefix, "Library", "bin", "ffmpeg.exe")
    else:
        exe = os.path.join(sys.prefix, "bin", "ffmpeg")
    if exe and os.path.isfile(exe) and _is_valid_exe(exe):
        return exe

    # 4. Try system ffmpeg command
    exe = "ffmpeg"
    if _is_valid_exe(exe):
        return exe

    # Nothing was found
    raise RuntimeError(
        "No ffmpeg exe could be found. Install ffmpeg on your system, "
        "or set the IMAGEIO_FFMPEG_EXE environment variable."
    ) 

def is_venv(self):
        if (hasattr(sys, 'real_prefix')) or (hasattr(sys, 'base_prefix') and sys.base_prefix != sys.prefix):
            return os.sep + os.path.relpath(sys.prefix, constants.BASE_DIR)
        else:
            return False