Normalize package names

internal/backends/python/gen_pypi_map/gen_pypi_map.go

@@ -71,6 +71,13 @@ func cmd_test(args []string) {
 			return
 		}
 		fmt.Printf("Loaded %v stats\n", len(bqCache))
+		normalizedBqCache := make(map[string]int)
+
+		for name, count := range bqCache {
+			normalizedBqCache[normalizePackageName(name)] = count
+		}
+		bqCache = normalizedBqCache
+
 		packageList := []string{}
 		for pkgName, count := range bqCache {
 			if count < *testThreshold {

internal/backends/python/gen_pypi_map/package.go

@@ -0,0 +1,17 @@
+package main
+
+import (
+	"regexp"
+	"strings"
+)
+
+var normalizationPattern = regexp.MustCompile(`[-_.]+`)
+
+// normalizePackageName implements NormalizePackageName for the Python
+// backends.
+// See https://packaging.python.org/en/latest/specifications/name-normalization/
+func normalizePackageName(name string) string {
+	name = strings.ToLower(name)
+	name = normalizationPattern.ReplaceAllString(name, "-")
+	return name
+}