Update the pypi specific name transformations to match https://peps.p…

src/main/java/org/sonatype/goodies/packageurl/PackageUrlBuilder.java

@@ -19,6 +19,7 @@
 import java.util.Map.Entry;
 import java.util.SortedMap;
 import java.util.TreeMap;
+import java.util.regex.Pattern;
 
 import static java.util.Objects.requireNonNull;
 import static org.sonatype.goodies.packageurl.PackageUrlParser.parseNamespace;
@@ -38,6 +39,8 @@
  */
 public class PackageUrlBuilder
 {
+  private static final Pattern PYPI_NORMALIZED_NAME_PATTERN = Pattern.compile("[-_.]+");
+
   private boolean typeSpecificTransformations = true;
 
   private String type;
@@ -188,7 +191,8 @@ PackageUrl buildAndValidate(final boolean validate) {
           break;
 
         case "pypi":
-          correctedName = name.replace('_', '-');
+          // Equivalent of: https://peps.python.org/pep-0503/#normalized-names
+          correctedName = PYPI_NORMALIZED_NAME_PATTERN.matcher(name).replaceAll("-");
           correctedName = MoreStrings.lowerCase(correctedName);
           break;
       }

src/test/java/org/sonatype/goodies/packageurl/PackageUrlBuilderTest.groovy

@@ -189,12 +189,12 @@ class PackageUrlBuilderTest
 
   @Test
   void 'pypi name'() {
-    PackageUrlBuilder builder = new PackageUrlBuilder().type('pypi').name('fOo-BaR_baZ')
+    PackageUrlBuilder builder = new PackageUrlBuilder().type('pypi').name('fOo--BaR_.baZ')
     builder.build().with {
       assert name == 'foo-bar-baz'
     }
     builder.typeSpecificTransformations(false).build().with {
-      assert name == 'fOo-BaR_baZ'
+      assert name == 'fOo--BaR_.baZ'
     }
   }
 

src/test/java/org/sonatype/goodies/packageurl/PackageUrlParserTest.groovy

@@ -256,6 +256,28 @@ class PackageUrlParserTest
       assert version == '1.11.1'
     }
 
+    parse('pkg:pypi/p2.Loader@0.1.0').with {
+      assert type == 'pypi'
+      assert name == 'p2-loader'
+      assert version == '0.1.0'
+    }
+    parseAsIs('pkg:pypi/p2.Loader@0.1.0').with {
+      assert type == 'pypi'
+      assert name == 'p2.Loader'
+      assert version == '0.1.0'
+    }
+
+    parse('pkg:pypi/cmc-csci046-.data-structures@1.0.7').with {
+      assert type == 'pypi'
+      assert name == 'cmc-csci046-data-structures'
+      assert version == '1.0.7'
+    }
+    parseAsIs('pkg:pypi/cmc-csci046-.data-structures@1.0.7').with {
+      assert type == 'pypi'
+      assert name == 'cmc-csci046-.data-structures'
+      assert version == '1.0.7'
+    }
+
     parse('pkg:rpm/fedora/curl@7.50.3-1.fc25?arch=i386&distro=fedora-25').with {
       assert type == 'rpm'
       assert namespace == ['fedora']