diff -r eb018a4dad3c -r 63a81867eb17 Lib/test/test_str_jy.py
--- a/Lib/test/test_str_jy.py	Thu Jul 25 11:12:30 2013 -0700
+++ b/Lib/test/test_str_jy.py	Wed Aug 21 14:03:21 2013 -0700
@@ -53,6 +53,10 @@
         self.assertEquals("%+f" % -5, "-5.000000")
         self.assertEquals("%+f" % 5, "+5.000000")
 
+    def test_format_issue2075(self):
+        self.assertEquals("%#018x" % 14, "0x000000000000000e")
+        self.assertEquals("{:#018x}".format(14), "0x000000000000000e")
+        self.assertEquals("{:+#018X}".format(14), "+0X00000000000000E")
 
     def test_argument_count_exception(self):
         "exception thrown when too many or too few arguments for format string"
diff -r eb018a4dad3c -r 63a81867eb17 src/org/python/core/stringlib/InternalFormatSpec.java
--- a/src/org/python/core/stringlib/InternalFormatSpec.java	Thu Jul 25 11:12:30 2013 -0700
+++ b/src/org/python/core/stringlib/InternalFormatSpec.java	Wed Aug 21 14:03:21 2013 -0700
@@ -30,6 +30,28 @@
             leading = 0;
         }
         char fill = fill_char != 0 ? fill_char : ' ';
+        switch (sign) {
+            case '+':
+            case ' ':
+                if (value.charAt(0) == sign) {
+                    result.append(sign);
+                    value = value.substring(1);
+                }
+                break;
+        }
+        if (alternate) {
+            char alt_char = value.charAt(1);
+            switch (alt_char) {
+                case 'b':
+                case 'o':
+                case 'x':
+                case 'X':
+                    result.append(value.charAt(0));
+                    result.append(value.charAt(1));
+                    value = value.substring(2);
+                    break;
+            }
+        }
         for (int i = 0; i < leading; i++) {
             result.append(fill);
         }