Add t-string support to pprint with expand=True

Author: hugovk

Lib/pprint.py

@@ -737,21 +737,53 @@ def _pprint_user_string(self, object, stream, indent, allowance, context, level)
 
     def _pprint_template(self, object, stream, indent, allowance, context, level):
         cls_name = object.__class__.__name__
-        indent += len(cls_name) + 1
-        items = (("strings", object.strings),
-                 ("interpolations", object.interpolations))
-        stream.write(cls_name + '(')
-        self._format_namespace_items(items, stream, indent, allowance, context, level)
-        stream.write(')')
+        if self._expand:
+            indent += self._indent_per_level
+        else:
+            indent += len(cls_name) + 1
+
+        items = (
+            ("strings", object.strings),
+            ("interpolations", object.interpolations),
+        )
+        stream.write(self._format_block_start(cls_name + "(", indent))
+        self._format_namespace_items(
+            items, stream, indent, allowance, context, level
+        )
+        stream.write(
+            self._format_block_end(")", indent - self._indent_per_level)
+        )
 
     def _pprint_interpolation(self, object, stream, indent, allowance, context, level):
         cls_name = object.__class__.__name__
-        indent += len(cls_name)
-        items = (object.value, object.expression,
-                object.conversion, object.format_spec)
-        stream.write(cls_name + '(')
-        self._format_items(items, stream, indent, allowance, context, level)
-        stream.write(')')
+        if self._expand:
+            indent += self._indent_per_level
+            items = (
+                ("value", object.value),
+                ("expression", object.expression),
+                ("conversion", object.conversion),
+                ("format_spec", object.format_spec),
+            )
+            stream.write(self._format_block_start(cls_name + "(", indent))
+            self._format_namespace_items(
+                items, stream, indent, allowance, context, level
+            )
+            stream.write(
+                self._format_block_end(")", indent - self._indent_per_level)
+            )
+        else:
+            indent += len(cls_name)
+            items = (
+                object.value,
+                object.expression,
+                object.conversion,
+                object.format_spec,
+            )
+            stream.write(cls_name + "(")
+            self._format_items(
+                items, stream, indent, allowance, context, level
+            )
+            stream.write(")")
 
     t = t"{0}"
     _dispatch[type(t).__repr__] = _pprint_template

Lib/test/test_pprint.py

@@ -1547,6 +1547,54 @@ def test_template(self):
                                        's',
                                        'z'),))""")
 
+    def test_expand_template(self):
+        d = t""
+        self.assertEqual(
+            pprint.pformat(d, expand=True),
+            "Template(strings=('',), interpolations=())",
+        )
+        name = "World"
+        d = t"Hello {name}"
+        self.assertEqual(
+            pprint.pformat(d, width=40, indent=4, expand=True),
+            """\
+Template(
+    strings=('Hello ', ''),
+    interpolations=(
+        Interpolation(
+            value='World',
+            expression='name',
+            conversion=None,
+            format_spec='',
+        ),
+    ),
+)""",
+        )
+        ver = {3.13: False, 3.14: True}
+        d = t"Hello { {"name": "Python", "version": ver}!s:z}!"
+        self.assertEqual(
+            pprint.pformat(d, width=40, indent=4, expand=True),
+            """\
+Template(
+    strings=('Hello ', '!'),
+    interpolations=(
+        Interpolation(
+            value={
+                'name': 'Python',
+                'version': {
+                    3.13: False,
+                    3.14: True,
+                },
+            },
+            expression=' {"name": "Python", '
+            '"version": ver}',
+            conversion='s',
+            format_spec='z',
+        ),
+    ),
+)""",
+        )
+
     def test_expand_dataclass(self):
         @dataclasses.dataclass
         class DummyDataclass: