--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/planemo/lib/python3.7/site-packages/virtualenv/seed/wheels/util.py	Fri Jul 31 00:32:28 2020 -0400
@@ -0,0 +1,116 @@
+from __future__ import absolute_import, unicode_literals
+
+from operator import attrgetter
+from zipfile import ZipFile
+
+from virtualenv.util.six import ensure_text
+
+
+class Wheel(object):
+    def __init__(self, path):
+        # https://www.python.org/dev/peps/pep-0427/#file-name-convention
+        # The wheel filename is {distribution}-{version}(-{build tag})?-{python tag}-{abi tag}-{platform tag}.whl
+        self.path = path
+        self._parts = path.stem.split("-")
+
+    @classmethod
+    def from_path(cls, path):
+        if path is not None and path.suffix == ".whl" and len(path.stem.split("-")) >= 5:
+            return cls(path)
+        return None
+
+    @property
+    def distribution(self):
+        return self._parts[0]
+
+    @property
+    def version(self):
+        return self._parts[1]
+
+    @property
+    def version_tuple(self):
+        return self.as_version_tuple(self.version)
+
+    @staticmethod
+    def as_version_tuple(version):
+        result = []
+        for part in version.split(".")[0:3]:
+            try:
+                result.append(int(part))
+            except ValueError:
+                break
+        if not result:
+            raise ValueError(version)
+        return tuple(result)
+
+    @property
+    def name(self):
+        return self.path.name
+
+    def support_py(self, py_version):
+        name = "{}.dist-info/METADATA".format("-".join(self.path.stem.split("-")[0:2]))
+        with ZipFile(ensure_text(str(self.path)), "r") as zip_file:
+            metadata = zip_file.read(name).decode("utf-8")
+        marker = "Requires-Python:"
+        requires = next((i[len(marker) :] for i in metadata.splitlines() if i.startswith(marker)), None)
+        if requires is None:  # if it does not specify a python requires the assumption is compatible
+            return True
+        py_version_int = tuple(int(i) for i in py_version.split("."))
+        for require in (i.strip() for i in requires.split(",")):
+            # https://www.python.org/dev/peps/pep-0345/#version-specifiers
+            for operator, check in [
+                ("!=", lambda v: py_version_int != v),
+                ("==", lambda v: py_version_int == v),
+                ("<=", lambda v: py_version_int <= v),
+                (">=", lambda v: py_version_int >= v),
+                ("<", lambda v: py_version_int < v),
+                (">", lambda v: py_version_int > v),
+            ]:
+                if require.startswith(operator):
+                    ver_str = require[len(operator) :].strip()
+                    version = tuple((int(i) if i != "*" else None) for i in ver_str.split("."))[0:2]
+                    if not check(version):
+                        return False
+                    break
+        return True
+
+    def __repr__(self):
+        return "{}({})".format(self.__class__.__name__, self.path)
+
+    def __str__(self):
+        return str(self.path)
+
+
+def discover_wheels(from_folder, distribution, version, for_py_version):
+    wheels = []
+    for filename in from_folder.iterdir():
+        wheel = Wheel.from_path(filename)
+        if wheel and wheel.distribution == distribution:
+            if version is None or wheel.version == version:
+                if wheel.support_py(for_py_version):
+                    wheels.append(wheel)
+    return sorted(wheels, key=attrgetter("version_tuple", "distribution"), reverse=True)
+
+
+class Version:
+    #: the version bundled with virtualenv
+    bundle = "bundle"
+    embed = "embed"
+    #: custom version handlers
+    non_version = (
+        bundle,
+        embed,
+    )
+
+    @staticmethod
+    def of_version(value):
+        return None if value in Version.non_version else value
+
+    @staticmethod
+    def as_pip_req(distribution, version):
+        return "{}{}".format(distribution, Version.as_version_spec(version))
+
+    @staticmethod
+    def as_version_spec(version):
+        of_version = Version.of_version(version)
+        return "" if of_version is None else "=={}".format(of_version)