login page

Lib/site-packages/pipenv/vendor/passa/internals/candidates.py

@@ -0,0 +1,86 @@
+# -*- coding=utf-8 -*-
+
+from __future__ import absolute_import, unicode_literals
+
+import packaging.specifiers
+import packaging.version
+import requirementslib
+
+from ._pip import find_installation_candidates, get_vcs_ref
+
+
+def _filter_matching_python_requirement(candidates, required_python):
+    # TODO: This should also takes the parent's python_version and
+    # python_full_version markers, and only return matches with valid
+    # intersections. For example, if parent requires `python_version >= '3.0'`,
+    # this should not return entries with "Requires-Python: <3".
+    for c in candidates:
+        try:
+            requires_python = c.requires_python
+        except AttributeError:
+            requires_python = c.location.requires_python
+        if required_python and requires_python:
+            # Old specifications had people setting this to single digits
+            # which is effectively the same as '>=digit,<digit+1'
+            if requires_python.isdigit():
+                requires_python = '>={0},<{1}'.format(
+                    requires_python, int(requires_python) + 1,
+                )
+            try:
+                specset = packaging.specifiers.SpecifierSet(requires_python)
+            except packaging.specifiers.InvalidSpecifier:
+                continue
+            if not specset.contains(required_python):
+                continue
+        yield c
+
+
+def _copy_requirement(requirement):
+    # Markers are intentionally dropped here. They will be added to candidates
+    # after resolution, so we can perform marker aggregation.
+    new = requirement.copy()
+    new.markers = None
+    return new
+
+
+def _requirement_from_metadata(name, version, extras, index):
+    # Markers are intentionally dropped here. They will be added to candidates
+    # after resolution, so we can perform marker aggregation.
+    r = requirementslib.Requirement.from_metadata(name, version, extras, None)
+    r.index = index
+    return r
+
+
+def find_candidates(requirement, sources, requires_python, allow_prereleases):
+    # A non-named requirement has exactly one candidate that is itself. For
+    # VCS, we also lock the requirement to an exact ref.
+    if not requirement.is_named:
+        candidate = _copy_requirement(requirement)
+        if candidate.is_vcs:
+            candidate.req.ref = get_vcs_ref(candidate)
+        return [candidate]
+
+    ireq = requirement.as_ireq()
+    icans = find_installation_candidates(ireq, sources)
+
+    if requires_python:
+        matching_icans = list(_filter_matching_python_requirement(
+            icans, packaging.version.parse(requires_python),
+        ))
+        icans = matching_icans or icans
+
+    versions = sorted(ireq.specifier.filter(
+        (c.version for c in icans), allow_prereleases,
+    ))
+    if not allow_prereleases and not versions:
+        versions = sorted(ireq.specifier.filter(
+            (c.version for c in icans), True,
+        ))
+
+    name = requirement.normalized_name
+    extras = requirement.extras
+    index = requirement.index
+    return [
+        _requirement_from_metadata(name, version, extras, index)
+        for version in versions
+    ]