--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/env/lib/python3.7/site-packages/virtualenv/discovery/py_info.py	Sat May 02 07:14:21 2020 -0400
@@ -0,0 +1,472 @@
+"""
+The PythonInfo contains information about a concrete instance of a Python interpreter
+
+Note: this file is also used to query target interpreters, so can only use standard library methods
+"""
+from __future__ import absolute_import, print_function
+
+import json
+import logging
+import os
+import platform
+import re
+import sys
+import sysconfig
+from collections import OrderedDict, namedtuple
+from distutils import dist
+from distutils.command.install import SCHEME_KEYS
+from string import digits
+
+VersionInfo = namedtuple("VersionInfo", ["major", "minor", "micro", "releaselevel", "serial"])
+
+
+def _get_path_extensions():
+    return list(OrderedDict.fromkeys([""] + os.environ.get("PATHEXT", "").lower().split(os.pathsep)))
+
+
+EXTENSIONS = _get_path_extensions()
+_CONF_VAR_RE = re.compile(r"\{\w+\}")
+
+
+class PythonInfo(object):
+    """Contains information for a Python interpreter"""
+
+    def __init__(self):
+        def u(v):
+            return v.decode("utf-8") if isinstance(v, bytes) else v
+
+        def abs_path(v):
+            return None if v is None else os.path.abspath(v)  # unroll relative elements from path (e.g. ..)
+
+        # qualifies the python
+        self.platform = u(sys.platform)
+        self.implementation = u(platform.python_implementation())
+        if self.implementation == "PyPy":
+            self.pypy_version_info = tuple(u(i) for i in sys.pypy_version_info)
+
+        # this is a tuple in earlier, struct later, unify to our own named tuple
+        self.version_info = VersionInfo(*list(u(i) for i in sys.version_info))
+        self.architecture = 64 if sys.maxsize > 2 ** 32 else 32
+
+        self.version = u(sys.version)
+        self.os = u(os.name)
+
+        # information about the prefix - determines python home
+        self.prefix = u(abs_path(getattr(sys, "prefix", None)))  # prefix we think
+        self.base_prefix = u(abs_path(getattr(sys, "base_prefix", None)))  # venv
+        self.real_prefix = u(abs_path(getattr(sys, "real_prefix", None)))  # old virtualenv
+
+        # information about the exec prefix - dynamic stdlib modules
+        self.base_exec_prefix = u(abs_path(getattr(sys, "base_exec_prefix", None)))
+        self.exec_prefix = u(abs_path(getattr(sys, "exec_prefix", None)))
+
+        self.executable = u(abs_path(sys.executable))  # the executable we were invoked via
+        self.original_executable = u(abs_path(self.executable))  # the executable as known by the interpreter
+        self.system_executable = self._fast_get_system_executable()  # the executable we are based of (if available)
+
+        try:
+            __import__("venv")
+            has = True
+        except ImportError:
+            has = False
+        self.has_venv = has
+        self.path = [u(i) for i in sys.path]
+        self.file_system_encoding = u(sys.getfilesystemencoding())
+        self.stdout_encoding = u(getattr(sys.stdout, "encoding", None))
+
+        self.sysconfig_paths = {u(i): u(sysconfig.get_path(i, expand=False)) for i in sysconfig.get_path_names()}
+        config_var_keys = set()
+        for element in self.sysconfig_paths.values():
+            for k in _CONF_VAR_RE.findall(element):
+                config_var_keys.add(u(k[1:-1]))
+        config_var_keys.add("PYTHONFRAMEWORK")
+
+        self.sysconfig_vars = {u(i): u(sysconfig.get_config_var(i) or "") for i in config_var_keys}
+        if self.implementation == "PyPy" and sys.version_info.major == 2:
+            self.sysconfig_vars[u"implementation_lower"] = u"python"
+
+        self.distutils_install = {u(k): u(v) for k, v in self._distutils_install().items()}
+        confs = {k: (self.system_prefix if v.startswith(self.prefix) else v) for k, v in self.sysconfig_vars.items()}
+        self.system_stdlib = self.sysconfig_path("stdlib", confs)
+        self.system_stdlib_platform = self.sysconfig_path("platstdlib", confs)
+        self.max_size = getattr(sys, "maxsize", getattr(sys, "maxint", None))
+        self._creators = None
+
+    def _fast_get_system_executable(self):
+        """Try to get the system executable by just looking at properties"""
+        if self.real_prefix or (
+            self.base_prefix is not None and self.base_prefix != self.prefix
+        ):  # if this is a virtual environment
+            if self.real_prefix is None:
+                base_executable = getattr(sys, "_base_executable", None)  # some platforms may set this to help us
+                if base_executable is not None:  # use the saved system executable if present
+                    if sys.executable != base_executable:  # we know we're in a virtual environment, cannot be us
+                        return base_executable
+            return None  # in this case we just can't tell easily without poking around FS and calling them, bail
+        # if we're not in a virtual environment, this is already a system python, so return the original executable
+        # note we must choose the original and not the pure executable as shim scripts might throw us off
+        return self.original_executable
+
+    @staticmethod
+    def _distutils_install():
+        # follow https://github.com/pypa/pip/blob/master/src/pip/_internal/locations.py#L95
+        # note here we don't import Distribution directly to allow setuptools to patch it
+        d = dist.Distribution({"script_args": "--no-user-cfg"})  # conf files not parsed so they do not hijack paths
+        if hasattr(sys, "_framework"):
+            sys._framework = None  # disable macOS static paths for framework
+        i = d.get_command_obj("install", create=True)
+        i.prefix = os.sep  # paths generated are relative to prefix that contains the path sep, this makes it relative
+        i.finalize_options()
+        result = {key: (getattr(i, "install_{}".format(key))[1:]).lstrip(os.sep) for key in SCHEME_KEYS}
+        return result
+
+    @property
+    def version_str(self):
+        return ".".join(str(i) for i in self.version_info[0:3])
+
+    @property
+    def version_release_str(self):
+        return ".".join(str(i) for i in self.version_info[0:2])
+
+    @property
+    def python_name(self):
+        version_info = self.version_info
+        return "python{}.{}".format(version_info.major, version_info.minor)
+
+    @property
+    def is_old_virtualenv(self):
+        return self.real_prefix is not None
+
+    @property
+    def is_venv(self):
+        return self.base_prefix is not None and self.version_info.major == 3
+
+    def sysconfig_path(self, key, config_var=None, sep=os.sep):
+        pattern = self.sysconfig_paths[key]
+        if config_var is None:
+            config_var = self.sysconfig_vars
+        else:
+            base = {k: v for k, v in self.sysconfig_vars.items()}
+            base.update(config_var)
+            config_var = base
+        return pattern.format(**config_var).replace(u"/", sep)
+
+    def creators(self, refresh=False):
+        if self._creators is None or refresh is True:
+            from virtualenv.run.plugin.creators import CreatorSelector
+
+            self._creators = CreatorSelector.for_interpreter(self)
+        return self._creators
+
+    @property
+    def system_include(self):
+        path = self.sysconfig_path(
+            "include",
+            {k: (self.system_prefix if v.startswith(self.prefix) else v) for k, v in self.sysconfig_vars.items()},
+        )
+        if not os.path.exists(path):  # some broken packaging don't respect the sysconfig, fallback to distutils path
+            # the pattern include the distribution name too at the end, remove that via the parent call
+            fallback = os.path.join(self.prefix, os.path.dirname(self.distutils_install["headers"]))
+            if os.path.exists(fallback):
+                path = fallback
+        return path
+
+    @property
+    def system_prefix(self):
+        return self.real_prefix or self.base_prefix or self.prefix
+
+    @property
+    def system_exec_prefix(self):
+        return self.real_prefix or self.base_exec_prefix or self.exec_prefix
+
+    def __unicode__(self):
+        content = repr(self)
+        if sys.version_info == 2:
+            content = content.decode("utf-8")
+        return content
+
+    def __repr__(self):
+        return "{}({!r})".format(
+            self.__class__.__name__, {k: v for k, v in self.__dict__.items() if not k.startswith("_")}
+        )
+
+    def __str__(self):
+        content = "{}({})".format(
+            self.__class__.__name__,
+            ", ".join(
+                "{}={}".format(k, v)
+                for k, v in (
+                    ("spec", self.spec,),
+                    (
+                        "system"
+                        if self.system_executable is not None and self.system_executable != self.executable
+                        else None,
+                        self.system_executable,
+                    ),
+                    (
+                        "original"
+                        if (
+                            self.original_executable != self.system_executable
+                            and self.original_executable != self.executable
+                        )
+                        else None,
+                        self.original_executable,
+                    ),
+                    ("exe", self.executable),
+                    ("platform", self.platform),
+                    ("version", repr(self.version)),
+                    ("encoding_fs_io", "{}-{}".format(self.file_system_encoding, self.stdout_encoding)),
+                )
+                if k is not None
+            ),
+        )
+        return content
+
+    @property
+    def spec(self):
+        return "{}{}-{}".format(self.implementation, ".".join(str(i) for i in self.version_info), self.architecture)
+
+    @classmethod
+    def clear_cache(cls, app_data):
+        # this method is not used by itself, so here and called functions can import stuff locally
+        from virtualenv.discovery.cached_py_info import clear
+
+        clear(app_data)
+        cls._cache_exe_discovery.clear()
+
+    def satisfies(self, spec, impl_must_match):
+        """check if a given specification can be satisfied by the this python interpreter instance"""
+        if spec.path:
+            if self.executable == os.path.abspath(spec.path):
+                return True  # if the path is a our own executable path we're done
+            if not spec.is_abs:
+                # if path set, and is not our original executable name, this does not match
+                basename = os.path.basename(self.original_executable)
+                spec_path = spec.path
+                if sys.platform == "win32":
+                    basename, suffix = os.path.splitext(basename)
+                    if spec_path.endswith(suffix):
+                        spec_path = spec_path[: -len(suffix)]
+                if basename != spec_path:
+                    return False
+
+        if impl_must_match:
+            if spec.implementation is not None and spec.implementation.lower() != self.implementation.lower():
+                return False
+
+        if spec.architecture is not None and spec.architecture != self.architecture:
+            return False
+
+        for our, req in zip(self.version_info[0:3], (spec.major, spec.minor, spec.micro)):
+            if req is not None and our is not None and our != req:
+                return False
+        return True
+
+    _current_system = None
+    _current = None
+
+    @classmethod
+    def current(cls, app_data=None):
+        """
+        This locates the current host interpreter information. This might be different than what we run into in case
+        the host python has been upgraded from underneath us.
+        """
+        if cls._current is None:
+            cls._current = cls.from_exe(sys.executable, app_data, raise_on_error=True, resolve_to_host=False)
+        return cls._current
+
+    @classmethod
+    def current_system(cls, app_data=None):
+        """
+        This locates the current host interpreter information. This might be different than what we run into in case
+        the host python has been upgraded from underneath us.
+        """
+        if cls._current_system is None:
+            cls._current_system = cls.from_exe(sys.executable, app_data, raise_on_error=True, resolve_to_host=True)
+        return cls._current_system
+
+    def _to_json(self):
+        # don't save calculated paths, as these are non primitive types
+        return json.dumps(self._to_dict(), indent=2)
+
+    def _to_dict(self):
+        data = {var: (getattr(self, var) if var not in ("_creators",) else None) for var in vars(self)}
+        # noinspection PyProtectedMember
+        data["version_info"] = data["version_info"]._asdict()  # namedtuple to dictionary
+        return data
+
+    @classmethod
+    def from_exe(cls, exe, app_data=None, raise_on_error=True, ignore_cache=False, resolve_to_host=True):
+        """Given a path to an executable get the python information"""
+        # this method is not used by itself, so here and called functions can import stuff locally
+        from virtualenv.discovery.cached_py_info import from_exe
+
+        proposed = from_exe(cls, app_data, exe, raise_on_error=raise_on_error, ignore_cache=ignore_cache)
+        # noinspection PyProtectedMember
+        if isinstance(proposed, PythonInfo) and resolve_to_host:
+            proposed = proposed._resolve_to_system(app_data, proposed)
+        return proposed
+
+    @classmethod
+    def _from_json(cls, payload):
+        # the dictionary unroll here is to protect against pypy bug of interpreter crashing
+        raw = json.loads(payload)
+        return cls._from_dict({k: v for k, v in raw.items()})
+
+    @classmethod
+    def _from_dict(cls, data):
+        data["version_info"] = VersionInfo(**data["version_info"])  # restore this to a named tuple structure
+        result = cls()
+        result.__dict__ = {k: v for k, v in data.items()}
+        return result
+
+    @classmethod
+    def _resolve_to_system(cls, app_data, target):
+        start_executable = target.executable
+        prefixes = OrderedDict()
+        while target.system_executable is None:
+            prefix = target.real_prefix or target.base_prefix or target.prefix
+            if prefix in prefixes:
+                if len(prefixes) == 1:
+                    # if we're linking back to ourselves accept ourselves with a WARNING
+                    logging.info("%r links back to itself via prefixes", target)
+                    target.system_executable = target.executable
+                    break
+                for at, (p, t) in enumerate(prefixes.items(), start=1):
+                    logging.error("%d: prefix=%s, info=%r", at, p, t)
+                logging.error("%d: prefix=%s, info=%r", len(prefixes) + 1, prefix, target)
+                raise RuntimeError("prefixes are causing a circle {}".format("|".join(prefixes.keys())))
+            prefixes[prefix] = target
+            target = target.discover_exe(app_data, prefix=prefix, exact=False)
+        if target.executable != target.system_executable:
+            target = cls.from_exe(target.system_executable, app_data)
+        target.executable = start_executable
+        return target
+
+    _cache_exe_discovery = {}
+
+    def discover_exe(self, app_data, prefix, exact=True):
+        key = prefix, exact
+        if key in self._cache_exe_discovery and prefix:
+            logging.debug("discover exe from cache %s - exact %s: %r", prefix, exact, self._cache_exe_discovery[key])
+            return self._cache_exe_discovery[key]
+        logging.debug("discover exe for %s in %s", self, prefix)
+        # we don't know explicitly here, do some guess work - our executable name should tell
+        possible_names = self._find_possible_exe_names()
+        possible_folders = self._find_possible_folders(prefix)
+        discovered = []
+        for folder in possible_folders:
+            for name in possible_names:
+                info = self._check_exe(app_data, folder, name, exact, discovered)
+                if info is not None:
+                    self._cache_exe_discovery[key] = info
+                    return info
+        if exact is False and discovered:
+            info = self._select_most_likely(discovered, self)
+            folders = os.pathsep.join(possible_folders)
+            self._cache_exe_discovery[key] = info
+            logging.debug("no exact match found, chosen most similar of %s within base folders %s", info, folders)
+            return info
+        msg = "failed to detect {} in {}".format("|".join(possible_names), os.pathsep.join(possible_folders))
+        raise RuntimeError(msg)
+
+    def _check_exe(self, app_data, folder, name, exact, discovered):
+        exe_path = os.path.join(folder, name)
+        if not os.path.exists(exe_path):
+            return None
+        info = self.from_exe(exe_path, app_data, resolve_to_host=False, raise_on_error=False)
+        if info is None:  # ignore if for some reason we can't query
+            return None
+        for item in ["implementation", "architecture", "version_info"]:
+            found = getattr(info, item)
+            searched = getattr(self, item)
+            if found != searched:
+                if item == "version_info":
+                    found, searched = ".".join(str(i) for i in found), ".".join(str(i) for i in searched)
+                executable = info.executable
+                logging.debug("refused interpreter %s because %s differs %s != %s", executable, item, found, searched)
+                if exact is False:
+                    discovered.append(info)
+                break
+        else:
+            return info
+        return None
+
+    @staticmethod
+    def _select_most_likely(discovered, target):
+        # no exact match found, start relaxing our requirements then to facilitate system package upgrades that
+        # could cause this (when using copy strategy of the host python)
+        def sort_by(info):
+            # we need to setup some priority of traits, this is as follows:
+            # implementation, major, minor, micro, architecture, tag, serial
+            matches = [
+                info.implementation == target.implementation,
+                info.version_info.major == target.version_info.major,
+                info.version_info.minor == target.version_info.minor,
+                info.architecture == target.architecture,
+                info.version_info.micro == target.version_info.micro,
+                info.version_info.releaselevel == target.version_info.releaselevel,
+                info.version_info.serial == target.version_info.serial,
+            ]
+            priority = sum((1 << pos if match else 0) for pos, match in enumerate(reversed(matches)))
+            return priority
+
+        sorted_discovered = sorted(discovered, key=sort_by, reverse=True)  # sort by priority in decreasing order
+        most_likely = sorted_discovered[0]
+        return most_likely
+
+    def _find_possible_folders(self, inside_folder):
+        candidate_folder = OrderedDict()
+        executables = OrderedDict()
+        executables[os.path.realpath(self.executable)] = None
+        executables[self.executable] = None
+        executables[os.path.realpath(self.original_executable)] = None
+        executables[self.original_executable] = None
+        for exe in executables.keys():
+            base = os.path.dirname(exe)
+            # following path pattern of the current
+            if base.startswith(self.prefix):
+                relative = base[len(self.prefix) :]
+                candidate_folder["{}{}".format(inside_folder, relative)] = None
+
+        # or at root level
+        candidate_folder[inside_folder] = None
+        return list(i for i in candidate_folder.keys() if os.path.exists(i))
+
+    def _find_possible_exe_names(self):
+        name_candidate = OrderedDict()
+        for name in self._possible_base():
+            for at in (3, 2, 1, 0):
+                version = ".".join(str(i) for i in self.version_info[:at])
+                for arch in ["-{}".format(self.architecture), ""]:
+                    for ext in EXTENSIONS:
+                        candidate = "{}{}{}{}".format(name, version, arch, ext)
+                        name_candidate[candidate] = None
+        return list(name_candidate.keys())
+
+    def _possible_base(self):
+        possible_base = OrderedDict()
+        basename = os.path.splitext(os.path.basename(self.executable))[0].rstrip(digits)
+        possible_base[basename] = None
+        possible_base[self.implementation] = None
+        # python is always the final option as in practice is used by multiple implementation as exe name
+        if "python" in possible_base:
+            del possible_base["python"]
+        possible_base["python"] = None
+        for base in possible_base:
+            lower = base.lower()
+            yield lower
+            from virtualenv.info import fs_is_case_sensitive
+
+            if fs_is_case_sensitive():
+                if base != lower:
+                    yield base
+                upper = base.upper()
+                if upper != base:
+                    yield upper
+
+
+if __name__ == "__main__":
+    # dump a JSON representation of the current python
+    # noinspection PyProtectedMember
+    print(PythonInfo()._to_json())