set precedence on f-string expressions

astor/code_gen.py

@@ -604,6 +604,7 @@ def recurse(node):
                             if getattr(value, 'expr_text', None):
                                 self.write(value.expr_text)
                             else:
+                                set_precedence(value, value.value)
                                 self.visit(value.value)
                             if value.conversion != -1:
                                 self.write('!%s' % chr(value.conversion))

astor/op_util.py

@@ -34,6 +34,7 @@
         ExtSlice                1
     comprehension_target        1
            Tuple                0
+  FormattedValue                0
 
            Comma                1
        NamedExpr                1

docs/changelog.rst

@@ -2,6 +2,19 @@
 Release Notes
 =============
 
+0.8.1 - in development
+----------------------
+
+Bug fixes
+~~~~~~~~~
+
+* Fixed precedence issue for f-string expressions that caused
+  redundant parenthesis around expression.
+  (Reported by Ilya Kamenshchikov in `Issue 153`_ and fixed by Batuhan Taskaya in `PR 155`_.)
+
+.. _`Issue 153`: https://github.com/berkerpeksag/astor/issues/153
+.. _`PR 155`: https://github.com/berkerpeksag/astor/pull/155
+
 0.8.0 - 2019-05-19
 ------------------
 

tests/test_code_gen.py

@@ -456,6 +456,7 @@ def test_fstrings(self):
         x = f'{int(x)}'
         x = f'a{b:c}d'
         x = f'a{b!s:c{d}e}f'
+        x = f'{x + y}'
         x = f'""'
         x = f'"\\''
         """