Add note to explain the cast

uranusjr · uranusjr · commit b337f94c7861 · 2021-03-22T13:38:08.000+08:00
diff --git a/src/pip/_internal/resolution/resolvelib/factory.py b/src/pip/_internal/resolution/resolvelib/factory.py
@@ -456,6 +456,8 @@ def get_installation_error(
             and not cause.requirement.is_satisfied_by(self._python_candidate)
         ]
         if requires_python_causes:
+            # The comprehension above makes sure all Requirement instances are
+            # RequiresPythonRequirement, so let's cast for convinience.
             return self._report_requires_python_error(
                 cast("Sequence[ConflictCause]", requires_python_causes),
             )

Original file line number	Diff line number	Diff line change
`@@ -456,6 +456,8 @@ def get_installation_error(`
`456`	`456`	`and not cause.requirement.is_satisfied_by(self._python_candidate)`
`457`	`457`	`]`
`458`	`458`	`if requires_python_causes:`
	`459`	`+ # The comprehension above makes sure all Requirement instances are`
	`460`	`+ # RequiresPythonRequirement, so let's cast for convinience.`
`459`	`461`	`return self._report_requires_python_error(`
`460`	`462`	`cast("Sequence[ConflictCause]", requires_python_causes),`
`461`	`463`	`)`