diff --git a/mace/python/tools/binary_codegen.py b/mace/python/tools/binary_codegen.py
index 3c78e889b1c5f270fdf8f9853b2512b2e1562e5a..d04dee4b4b6512a7cb1f08b0c849341daac1de56 100644
--- a/mace/python/tools/binary_codegen.py
+++ b/mace/python/tools/binary_codegen.py
@@ -74,9 +74,8 @@ def tuning_param_codegen(binary_dirs,
             binary_dirs, binary_file_name, variable_name)
     if os.path.isfile(output_path):
         os.remove(output_path)
-    w_file = open(output_path, "w")
-    w_file.write(cpp_binary_source)
-    w_file.close()
+    with open(output_path, "w") as w_file:
+        w_file.write(cpp_binary_source)
 
 
 def parse_args():
diff --git a/mace/python/tools/encrypt_opencl_codegen.py b/mace/python/tools/encrypt_opencl_codegen.py
index 6292b8349e60154824807d070fe0f4802092db07..1c227ab98fe6aed5ed021dc342db589e65e0c6b6 100644
--- a/mace/python/tools/encrypt_opencl_codegen.py
+++ b/mace/python/tools/encrypt_opencl_codegen.py
@@ -44,22 +44,22 @@ def encrypt_opencl_codegen(cl_kernel_dir, output_path):
     for file_name in os.listdir(cl_kernel_dir):
         file_path = os.path.join(cl_kernel_dir, file_name)
         if file_path[-2:] == ".h":
-            f = open(file_path, "r")
-            header_code += f.read()
+            with open(file_path, "r") as f:
+                header_code += f.read()
 
     encrypted_code_maps = {}
     for file_name in os.listdir(cl_kernel_dir):
         file_path = os.path.join(cl_kernel_dir, file_name)
         if file_path[-3:] == ".cl":
-            f = open(file_path, "r")
-            code_str = ""
-            for line in f.readlines():
-                if "#include <common.h>" in line:
-                    code_str += header_code
-                else:
-                    code_str += line
-            encrypted_code_arr = encrypt_code(code_str)
-            encrypted_code_maps[file_name[:-3]] = encrypted_code_arr
+            with open(file_path, "r") as f:
+                code_str = ""
+                for line in f.readlines():
+                    if "#include <common.h>" in line:
+                        code_str += header_code
+                    else:
+                        code_str += line
+                encrypted_code_arr = encrypt_code(code_str)
+                encrypted_code_maps[file_name[:-3]] = encrypted_code_arr
 
     env = jinja2.Environment(loader=jinja2.FileSystemLoader(sys.path[0]))
     cpp_cl_encrypted_kernel = env.get_template(
@@ -70,9 +70,8 @@ def encrypt_opencl_codegen(cl_kernel_dir, output_path):
 
     if os.path.isfile(output_path):
         os.remove(output_path)
-    w_file = open(output_path, "w")
-    w_file.write(cpp_cl_encrypted_kernel)
-    w_file.close()
+    with open(output_path, "w") as w_file:
+        w_file.write(cpp_cl_encrypted_kernel)
 
     print("Generate encrypted opencl source done!")
 
diff --git a/mace/python/tools/opencl_codegen.py b/mace/python/tools/opencl_codegen.py
index cfb12f744b0b25d84099b8b82a4eeab75f9ef2f0..c21e5b974df0ff767607398336090c385b3a7608 100644
--- a/mace/python/tools/opencl_codegen.py
+++ b/mace/python/tools/opencl_codegen.py
@@ -86,9 +86,8 @@ def opencl_codegen(output_path,
                                                platform_info_file_name)
     if os.path.isfile(output_path):
         os.remove(output_path)
-    w_file = open(output_path, "w")
-    w_file.write(cpp_cl_binary_source)
-    w_file.close()
+    with open(output_path, "w") as w_file:
+        w_file.write(cpp_cl_binary_source)
 
 
 def parse_args():
diff --git a/mace/python/tools/source_converter_lib.py b/mace/python/tools/source_converter_lib.py
index 404e56b994460700d7c8b2a08782c11f859e236e..9d6bc8970d84b4c77303cce66798a4d3bb5bedb2 100644
--- a/mace/python/tools/source_converter_lib.py
+++ b/mace/python/tools/source_converter_lib.py
@@ -173,9 +173,8 @@ def convert_to_source(net_def, mode_pb_checksum, template_dir, obfuscate,
     with open(output_dir + 'tensor_data' + '.cc', "wb") as f:
         f.write(source)
     if not embed_model_data:
-        f = open(output_dir + model_tag + '.data', "wb")
-        f.write(bytearray(model_data))
-        f.close()
+        with open(output_dir + model_tag + '.data', "wb") as f:
+            f.write(bytearray(model_data))
 
     # generate op source files
     template_name = 'operator.jinja2'