honor space after comma option in formatter (PY-486)

python/src/com/jetbrains/python/formatter/PyBlock.java

@@ -215,6 +215,10 @@ public class PyBlock implements ASTBlock {
     if (type1 == PyTokenTypes.COLON && type2 == PyElementTypes.STATEMENT_LIST) {
       return Spacing.createSpacing(1, Integer.MAX_VALUE, 0, true, 0);
     }
+
+    if (type1 == PyTokenTypes.COMMA) {
+      return getSpacingForOption(mySettings.SPACE_AFTER_COMMA);
+    }
 /*
         if (type1 == PyTokenTypes.COLON && type2 == PyElementTypes.STATEMENT_LIST) {
             return Spacing.createSpacing(0, Integer.MAX_VALUE, 1, true, Integer.MAX_VALUE);
@@ -239,6 +243,11 @@ public class PyBlock implements ASTBlock {
     return null;
   }
 
+  private Spacing getSpacingForOption(boolean isOptionSet) {
+    int spaces = isOptionSet ? 1 : 0;
+    return Spacing.createSpacing(spaces, spaces, 0, mySettings.KEEP_LINE_BREAKS, mySettings.KEEP_BLANK_LINES_IN_CODE);
+  }
+
   private static boolean isStatementOrDeclaration(final IElementType type) {
     return PyElementTypes.STATEMENTS.contains(type) ||
            type == PyElementTypes.CLASS_DECLARATION || 

python/testData/formatter/spaceAfterComma.py

@@ -0,0 +1 @@
+import os,sys

python/testData/formatter/spaceAfterComma_after.py

@@ -0,0 +1 @@
+import os, sys

python/testSrc/com/jetbrains/python/PyFormatterTest.java

@@ -16,6 +16,10 @@ public class PyFormatterTest extends PyLightFixtureTestCase {
     doTest();
   }
 
+  public void testSpaceAfterComma() throws Exception {
+    doTest();
+  }
+
   private void doTest() throws Exception {
     myFixture.configureByFile("formatter/" + getTestName(true) + ".py");
     ApplicationManager.getApplication().runWriteAction(new Runnable() {