@@ -628,33 +628,51 @@ def test_missing_expression(self):
                             ["f'{}'",
                              "f'{ }'"
                              "f' {} '",
-                             "f'{!r}'",
-                             "f'{ !r}'",
                              "f'{10:{ }}'",
                              "f' { } '",
 
                              # The Python parser ignores also the following
                              # whitespace characters in additional to a space.
                              "f'''{\t\f\r\n}'''",
+                             ])
+
+        # Different error messeges are raised when a specfier ('!', ':' or '=') is used after an empty expression
+        self.assertAllRaise(SyntaxError, "f-string: expression required before '!'",
+                            ["f'{!r}'",
+                             "f'{ !r}'",
+                             "f'{!}'",
+                             "f'''{\t\f\r\n!a}'''",
+
+                             # Catch empty expression before the
+                             #  missing closing brace.
+                             "f'{!'",
+                             "f'{!s:'",
 
-                             # Catch the empty expression before the
+                             # Catch empty expression before the
                              #  invalid conversion.
                              "f'{!x}'",
                              "f'{ !xr}'",
                              "f'{!x:}'",
                              "f'{!x:a}'",
                              "f'{ !xr:}'",
                              "f'{ !xr:a}'",
+                             ])
 
-                             "f'{!}'",
-                             "f'{:}'",
-
-                             # We find the empty expression before the
-                             #  missing closing brace.
-                             "f'{!'",
-                             "f'{!s:'",
+        self.assertAllRaise(SyntaxError, "f-string: expression required before ':'",
+                            ["f'{:}'",
+                             "f'{ :!}'",
+                             "f'{:2}'",
+                             "f'''{\t\f\r\n:a}'''",
                              "f'{:'",
-                             "f'{:x'",
+                             ])
+
+        self.assertAllRaise(SyntaxError, "f-string: expression required before '='",
+                            ["f'{=}'",
+                             "f'{ =}'",
+                             "f'{ =:}'",
+                             "f'{   =!}'",
+                             "f'''{\t\f\r\n=}'''",
+                             "f'{='",
                              ])
 
         # Different error message is raised for other whitespace characters.
 
@@ -0,0 +1 @@
+Improve error messages in f-string syntax errors concerning empty expressions.
@@ -357,7 +357,12 @@ fstring_compile_expr(Parser *p, const char *expr_start, const char *expr_end,
             break;
         }
     }
+    
     if (s == expr_end) {
+        if (*expr_end == '!' || *expr_end == ':' || *expr_end == '=') {
+            RAISE_SYNTAX_ERROR("f-string: expression required before '%c'", *expr_end);
+            return NULL;
+        }
         RAISE_SYNTAX_ERROR("f-string: empty expression not allowed");
         return NULL;
     }
Original file line number	Diff line number	Diff line change
@@ -0,0 +1 @@
	1	+ Improve error messages in f-string syntax errors concerning empty expressions.
Original file line number	Diff line number	Diff line change
@@ -357,7 +357,12 @@ fstring_compile_expr(Parser p, const char expr_start, const char *expr_end,
357	357	break;
358	358	}
359	359	}
	360	+
360	361	if (s == expr_end) {
	362	+ if (expr_end == '!' \|\| expr_end == ':' \|\| *expr_end == '=') {
	363	+ RAISE_SYNTAX_ERROR("f-string: expression required before '%c'", *expr_end);
	364	+ return NULL;
	365	+ }
361	366	RAISE_SYNTAX_ERROR("f-string: empty expression not allowed");
362	367	return NULL;
363	368	}