[CodeStyle][F402] Change the loop variable name which is the same with an imported module (#46698)

* Update README.md

* Update README.md

* Fix F402 by changing the name of loop variable

* Change variable name
Change variable name 'temp_tensor' to 'var' to avoid confusion, as var
also appears in the same file.

python/paddle/fluid/tests/unittests/test_auto_parallel_partitioner.py

@@ -234,9 +234,8 @@ def distributed_attr_check_for_dist_op(serial_main_prog, dist_main_prog,
 def distributed_attr_check_for_program(dist_main_prog, dist_context):
     have_dist_attr = True
     for block in dist_main_prog.blocks:
-        for tensor in block.vars.values():
-            var_dist_attr = dist_context.get_tensor_dist_attr_for_program(
-                tensor)
+        for var in block.vars.values():
+            var_dist_attr = dist_context.get_tensor_dist_attr_for_program(var)
             if var_dist_attr is None:
                 have_dist_attr = False