Remove unused variable.

This variable was not being used and caused some confusion when
updating the list of reviewers, so we remove it and try to update a
comment to explain its purpose.

Test: atest external_updater_reviewers_test
Change-Id: Ieab960b9b7bbdef678b3c3c05f2bdc33c76fa407

2 files changed, 4 insertions, 15 deletions

diff --git a/external_updater_reviewers_test.py b/external_updater_reviewers_test.py
index d6e4b71..18497f5 100644
--- a/external_updater_reviewers_test.py
+++ b/external_updater_reviewers_test.py
@@ -28,7 +28,6 @@ class ExternalUpdaterReviewersTest(unittest.TestCase):
         self.saved_proj_reviewers = reviewers.PROJ_REVIEWERS
         self.saved_rust_reviewers = reviewers.RUST_REVIEWERS
         self.saved_rust_reviewer_list = reviewers.RUST_REVIEWER_LIST
-        self.saved_num_rust_projects = reviewers.NUM_RUST_PROJECTS
         self.saved_rust_crate_owners = reviewers.RUST_CRATE_OWNERS
 
     def tearDown(self):
@@ -37,7 +36,6 @@ class ExternalUpdaterReviewersTest(unittest.TestCase):
         reviewers.PROJ_REVIEWERS = self.saved_proj_reviewers
         reviewers.RUST_REVIEWERS = self.saved_rust_reviewers
         reviewers.RUST_REVIEWER_LIST = self.saved_rust_reviewer_list
-        reviewers.NUM_RUST_PROJECTS = self.saved_num_rust_projects
         reviewers.RUST_CRATE_OWNERS = self.saved_rust_crate_owners
 
     # pylint: disable=no-self-use
@@ -74,16 +72,11 @@ class ExternalUpdaterReviewersTest(unittest.TestCase):
         """Check the constants associated to the reviewers."""
         # There should be enough people in the reviewers pool.
         self.assertGreaterEqual(len(reviewers.RUST_REVIEWERS), 3)
-        # The NUM_RUST_PROJECTS should not be too small.
-        self.assertGreaterEqual(reviewers.NUM_RUST_PROJECTS, 50)
-        self.assertGreaterEqual(reviewers.NUM_RUST_PROJECTS,
-                                len(reviewers.RUST_CRATE_OWNERS))
         # Assume no project reviewers and recreate RUST_REVIEWER_LIST
         reviewers.PROJ_REVIEWERS = {}
         reviewers.RUST_REVIEWER_LIST = reviewers.create_rust_reviewer_list()
         sum_projects = sum(reviewers.RUST_REVIEWERS.values())
         self.assertEqual(sum_projects, len(reviewers.RUST_REVIEWER_LIST))
-        self.assertGreaterEqual(sum_projects, reviewers.NUM_RUST_PROJECTS)
 
     def test_reviewers_randomness(self):
         """Check random selection of reviewers."""
diff --git a/reviewers.py b/reviewers.py
index 6f826f1..70377cd 100644
--- a/reviewers.py
+++ b/reviewers.py
@@ -31,6 +31,7 @@ ProjMapping = Mapping[str, Union[str, List[str], Set[str]]]
 RUST_CRATE_OWNERS: ProjMapping = {
     'rust/crates/anyhow': 'mmaurer@google.com',
     # more rust crate owners could be added later
+    # if so, consider modifying the quotas in RUST_REVIEWERS
 }
 
 PROJ_REVIEWERS: ProjMapping = {
@@ -40,16 +41,11 @@ PROJ_REVIEWERS: ProjMapping = {
 # Combine all roject reviewers.
 PROJ_REVIEWERS.update(RUST_CRATE_OWNERS)
 
-# Estimated number of rust projects, not the actual number.
-# It is only used to make random distribution "fair" among RUST_REVIEWERS.
-# It should not be too small, to spread nicely to multiple reviewers.
-# It should be larger or equal to len(RUST_CRATES_OWNERS).
-NUM_RUST_PROJECTS = 120
-
 # Reviewers for external/rust/crates projects not found in PROJ_REVIEWER.
 # Each person has a quota, the number of projects to review.
-# Sum of these numbers should be greater or equal to NUM_RUST_PROJECTS
-# to avoid error cases in the creation of RUST_REVIEWER_LIST.
+# The sum of these quotas should ideally be at least the number of Rust
+# projects, but this only matters if we have many entries in RUST_CRATE_OWNERS,
+# as we subtract a person's owned crates from their quota.
 RUST_REVIEWERS: Mapping[str, int] = {
     'ivanlozano@google.com': 20,
     'jeffv@google.com': 20,