[Lang] Support f-string

python/taichi/lang/expr_builder.py

@@ -9,6 +9,28 @@
 
 
 class ExprBuilder(Builder):
+    @staticmethod
+    def build_JoinedStr(ctx, node):
+        str_spec = ''
+        args = []
+        for sub_node in node.values:
+            if isinstance(sub_node, ast.FormattedValue):
+                str_spec += '{}'
+                args.append(build_expr(ctx, sub_node.value))
+            elif isinstance(sub_node, ast.Constant):
+                str_spec += sub_node.value
+            elif isinstance(sub_node, ast.Str):
+                # ast.Str has been deprecated in Python 3.8,
+                # but constant string is a ast.Str node in Python 3.6
+                str_spec += sub_node.s
+
+        args.insert(0, ast.copy_location(ast.Constant(value=str_spec), node))
+
+        call = ast.Call(func=parse_expr('ti.ti_format'),
+                        args=args,
+                        keywords=[])
+        return ast.copy_location(call, node)
+
     @staticmethod
     def build_Subscript(ctx, node):
         def get_subscript_index(node):

tests/python/test_print.py

@@ -142,3 +142,16 @@ def func(k: ti.f32):
 
     func(233.3)
     ti.sync()
+
+
+@ti.test(arch=ti.cpu)
+def test_print_fstring():
+    def foo1(x):
+        return x + 1
+
+    @ti.kernel
+    def func(i: ti.i32, f: ti.f32):
+        print(f'qwe {foo1(1)} {foo1(2) * 2 - 1} {i} {f} {4} {True} {1.23}')
+
+    func(123, 4.56)
+    ti.sync()