diff --git a/examples/dataset_image_workflow/get_data.py b/examples/dataset_image_workflow/get_data.py
index e0ee9bc..c3af534 100644
--- a/examples/dataset_image_workflow/get_data.py
+++ b/examples/dataset_image_workflow/get_data.py
@@ -192,7 +192,7 @@ def get_zca_matrix(X, reg_coef=0.1):
 
 def layernorm_data(X):
     X_processed = X - torch.mean(X, [1, 2, 3], keepdim=True)
-    X_processed = X_processed / torch.sqrt(torch.sum(X_processed ** 2, [1, 2, 3], keepdim=True))
+    X_processed = X_processed / torch.sqrt(torch.sum(X_processed**2, [1, 2, 3], keepdim=True))
 
     return X_processed
 
@@ -240,7 +240,10 @@ def augment(images, dc_aug_param, device):
         def scalefun(i):
             h = int((np.random.uniform(1 - scale, 1 + scale)) * shape[2])
             w = int((np.random.uniform(1 - scale, 1 + scale)) * shape[2])
-            tmp = F.interpolate(images[i : i + 1], [h, w],)[0]
+            tmp = F.interpolate(
+                images[i : i + 1],
+                [h, w],
+            )[0]
             mhw = max(h, w, shape[2], shape[3])
             im_ = torch.zeros(shape[1], mhw, mhw, dtype=torch.float, device=device)
             r = int((mhw - h) / 2)
diff --git a/examples/dataset_m5_workflow/m5/utils.py b/examples/dataset_m5_workflow/m5/utils.py
index c21a297..721eee2 100644
--- a/examples/dataset_m5_workflow/m5/utils.py
+++ b/examples/dataset_m5_workflow/m5/utils.py
@@ -70,7 +70,7 @@ def measure_aux_algo(idx, test_sample, model):
 
 # Simple "Memory profilers" to see memory usage
 def get_memory_usage():
-    return np.round(psutil.Process(os.getpid()).memory_info()[0] / 2.0 ** 30, 2)
+    return np.round(psutil.Process(os.getpid()).memory_info()[0] / 2.0**30, 2)
 
 
 def sizeof_fmt(num, suffix="B"):
@@ -84,7 +84,7 @@ def sizeof_fmt(num, suffix="B"):
 # Memory Reducer
 def reduce_mem_usage(df, float16_flag=True, verbose=True):
     numerics = ["int16", "int32", "int64", "float16", "float32", "float64"]
-    start_mem = df.memory_usage().sum() / 1024 ** 2
+    start_mem = df.memory_usage().sum() / 1024**2
     for col in df.columns:
         col_type = df[col].dtypes
         if col_type in numerics:
@@ -106,7 +106,7 @@ def reduce_mem_usage(df, float16_flag=True, verbose=True):
                     df[col] = df[col].astype(np.float32)
                 else:
                     df[col] = df[col].astype(np.float64)
-    end_mem = df.memory_usage().sum() / 1024 ** 2
+    end_mem = df.memory_usage().sum() / 1024**2
     if verbose:
         print(
             "Mem. usage decreased to {:5.2f} Mb ({:.1f}% reduction)".format(
diff --git a/examples/dataset_m5_workflow/upload.py b/examples/dataset_m5_workflow/upload.py
index 4e26c36..0c9e209 100644
--- a/examples/dataset_m5_workflow/upload.py
+++ b/examples/dataset_m5_workflow/upload.py
@@ -69,8 +69,15 @@ def main():
         }
         res = session.post(
             submit_url,
-            data={"semantic_specification": json.dumps(semantic_specification),},
-            files={"learnware_file": open(os.path.join(os.path.abspath("."), "learnware_pool", learnware), "rb",)},
+            data={
+                "semantic_specification": json.dumps(semantic_specification),
+            },
+            files={
+                "learnware_file": open(
+                    os.path.join(os.path.abspath("."), "learnware_pool", learnware),
+                    "rb",
+                )
+            },
         )
         assert json.loads(res.text)["code"] == 0, "Upload error"
 
diff --git a/examples/dataset_pfs_workflow/pfs/pfs_cross_transfer.py b/examples/dataset_pfs_workflow/pfs/pfs_cross_transfer.py
index a106fb7..93a3fa3 100644
--- a/examples/dataset_pfs_workflow/pfs/pfs_cross_transfer.py
+++ b/examples/dataset_pfs_workflow/pfs/pfs_cross_transfer.py
@@ -67,7 +67,7 @@ def get_split_errs(algo):
             for tmp in range(len(proportion_list)):
                 model = lgb.LGBMModel(
                     boosting_type="gbdt",
-                    num_leaves=2 ** 7 - 1,
+                    num_leaves=2**7 - 1,
                     learning_rate=0.01,
                     objective="rmse",
                     metric="rmse",
@@ -119,7 +119,7 @@ def get_errors(algo):
         if algo == "lgb":
             model = lgb.LGBMModel(
                 boosting_type="gbdt",
-                num_leaves=2 ** 7 - 1,
+                num_leaves=2**7 - 1,
                 learning_rate=0.01,
                 objective="rmse",
                 metric="rmse",
diff --git a/examples/dataset_pfs_workflow/upload.py b/examples/dataset_pfs_workflow/upload.py
index d09bc46..9719230 100644
--- a/examples/dataset_pfs_workflow/upload.py
+++ b/examples/dataset_pfs_workflow/upload.py
@@ -72,8 +72,15 @@ def main():
         }
         res = session.post(
             submit_url,
-            data={"semantic_specification": json.dumps(semantic_specification),},
-            files={"learnware_file": open(os.path.join(os.path.abspath("."), "learnware_pool", learnware), "rb",)},
+            data={
+                "semantic_specification": json.dumps(semantic_specification),
+            },
+            files={
+                "learnware_file": open(
+                    os.path.join(os.path.abspath("."), "learnware_pool", learnware),
+                    "rb",
+                )
+            },
         )
         assert json.loads(res.text)["code"] == 0, "Upload error"
 
diff --git a/examples/workflow_by_code/main.py b/examples/workflow_by_code/main.py
index 9eafb6e..3534aae 100644
--- a/examples/workflow_by_code/main.py
+++ b/examples/workflow_by_code/main.py
@@ -19,7 +19,10 @@ curr_root = os.path.dirname(os.path.abspath(__file__))
 
 user_semantic = {
     "Data": {"Values": ["Table"], "Type": "Class"},
-    "Task": {"Values": ["Classification"], "Type": "Class",},
+    "Task": {
+        "Values": ["Classification"],
+        "Type": "Class",
+    },
     "Library": {"Values": ["Scikit-learn"], "Type": "Class"},
     "Scenario": {"Values": ["Education"], "Type": "Tag"},
     "Description": {"Values": "", "Type": "String"},
diff --git a/learnware/client/container.py b/learnware/client/container.py
index a999e1d..15236b0 100644
--- a/learnware/client/container.py
+++ b/learnware/client/container.py
@@ -18,7 +18,6 @@ logger = get_module_logger(module_name="client_container")
 
 class ModelEnvContainer(BaseModel):
     def __init__(self, model_config: dict, learnware_zippath: str):
-
         self.model_script = os.path.join(C.package_path, "client", "scripts", "run_model.py")
         self.model_config = model_config
         self.conda_env = f"learnware_{shortuuid.uuid()}"
diff --git a/learnware/client/learnware_client.py b/learnware/client/learnware_client.py
index 8d25144..723267f 100644
--- a/learnware/client/learnware_client.py
+++ b/learnware/client/learnware_client.py
@@ -104,8 +104,13 @@ class LearnwareClient:
         for chunk in file_chunks(learnware_file):
             response = requests.post(
                 url_upload,
-                files={"chunk_file": chunk,},
-                data={"file_hash": file_hash, "chunk_begin": begin,},
+                files={
+                    "chunk_file": chunk,
+                },
+                data={
+                    "file_hash": file_hash,
+                    "chunk_begin": begin,
+                },
                 headers=self.headers,
             )
 
@@ -123,7 +128,10 @@ class LearnwareClient:
 
         response = requests.post(
             url_add,
-            json={"file_hash": file_hash, "semantic_specification": json.dumps(semantic_specification),},
+            json={
+                "file_hash": file_hash,
+                "semantic_specification": json.dumps(semantic_specification),
+            },
             headers=self.headers,
         )
 
@@ -137,7 +145,14 @@ class LearnwareClient:
     def download_learnware(self, learnware_id, save_path):
         url = f"{self.host}/engine/download_learnware"
 
-        response = requests.get(url, params={"learnware_id": learnware_id,}, headers=self.headers, stream=True,)
+        response = requests.get(
+            url,
+            params={
+                "learnware_id": learnware_id,
+            },
+            headers=self.headers,
+            stream=True,
+        )
 
         if response.status_code != 200:
             raise Exception("download failed: " + json.dumps(response.json()))
@@ -269,7 +284,6 @@ class LearnwareClient:
     def create_semantic_specification(
         self, name, description, data_type, task_type, library_type, senarioes, input_description, output_description
     ):
-
         semantic_specification = dict()
         semantic_specification["Input"] = input_description
         semantic_specification["Output"] = output_description
diff --git a/learnware/client/package_utils.py b/learnware/client/package_utils.py
index 0088bb4..06ff689 100644
--- a/learnware/client/package_utils.py
+++ b/learnware/client/package_utils.py
@@ -24,8 +24,7 @@ def try_to_run(args, timeout=5, retry=5):
 
 
 def parse_pip_requirement(line: str):
-    """Parse pip requirement line to package name
-    """
+    """Parse pip requirement line to package name"""
 
     line = line.strip()
 
@@ -47,8 +46,7 @@ def parse_pip_requirement(line: str):
 
 
 def read_pip_packages_from_requirements(requirements_file: str) -> List[str]:
-    """Read requiremnts.txt and parse it to list
-    """
+    """Read requiremnts.txt and parse it to list"""
 
     packages = []
     lines = []
@@ -174,7 +172,6 @@ def filter_nonexist_conda_packages_file(yaml_file: str, output_yaml_file: str):
 
 
 def filter_nonexist_pip_packages_file(requirements_file: str, output_file: str):
-
     packages, lines = read_pip_packages_from_requirements(requirements_file)
 
     exist_packages, nonexist_packages = filter_nonexist_pip_packages(packages)
diff --git a/learnware/client/utils.py b/learnware/client/utils.py
index d192c85..b6d9c8a 100644
--- a/learnware/client/utils.py
+++ b/learnware/client/utils.py
@@ -10,14 +10,11 @@ logger = get_module_logger(module_name="client_utils")
 
 
 def system_execute(args, timeout=None):
-
-    com_process = subprocess.run(
-        args, stdout=subprocess.DEVNULL, stderr=subprocess.PIPE, timeout=timeout
-    )
+    com_process = subprocess.run(args, stdout=subprocess.DEVNULL, stderr=subprocess.PIPE, timeout=timeout)
     try:
         com_process.check_returncode()
     except subprocess.CalledProcessError as err:
-        print(com_process.stderr)
+        print("System Execute Error:", str(com_process.stderr))
         raise err
 
 
@@ -27,14 +24,14 @@ def remove_enviroment(conda_env):
 
 def install_environment(zip_path, conda_env):
     """Install environment of a learnware
-    
+
     Parameters
     ----------
     zip_path : str
         Path of the learnware zip file
     conda_env : str
         a new conda environment will be created with the given name;
-        
+
     Raises
     ------
     Exception
@@ -59,7 +56,7 @@ def install_environment(zip_path, conda_env):
                 z_file.extract(member="requirements.txt", path=tempdir)
                 requirements_path: str = os.path.join(tempdir, "requirements.txt")
                 requirements_path_filter: str = os.path.join(tempdir, "requirements_filter.txt")
-                logger.info(f"checking the avaliabe pip packages for {yaml_path}")
+                logger.info(f"checking the avaliabe pip packages for {conda_env}")
                 filter_nonexist_pip_packages_file(
                     requirements_file=requirements_path, output_file=requirements_path_filter
                 )
diff --git a/learnware/config.py b/learnware/config.py
index 137f15b..7fdcc91 100644
--- a/learnware/config.py
+++ b/learnware/config.py
@@ -72,7 +72,10 @@ os.makedirs(DATABASE_PATH, exist_ok=True)
 os.makedirs(STDOUT_PATH, exist_ok=True)
 
 semantic_config = {
-    "Data": {"Values": ["Table", "Image", "Video", "Text", "Audio"], "Type": "Class",},  # Choose only one class
+    "Data": {
+        "Values": ["Table", "Image", "Video", "Text", "Audio"],
+        "Type": "Class",
+    },  # Choose only one class
     "Task": {
         "Values": [
             "Classification",
@@ -113,8 +116,14 @@ semantic_config = {
         ],
         "Type": "Tag",  # Choose one or more tags
     },
-    "Description": {"Values": None, "Type": "String",},
-    "Name": {"Values": None, "Type": "String",},
+    "Description": {
+        "Values": None,
+        "Type": "String",
+    },
+    "Name": {
+        "Values": None,
+        "Type": "String",
+    },
 }
 
 _DEFAULT_CONFIG = {
@@ -128,7 +137,10 @@ _DEFAULT_CONFIG = {
     "learnware_pool_path": LEARNWARE_POOL_PATH,
     "learnware_zip_pool_path": LEARNWARE_ZIP_POOL_PATH,
     "learnware_folder_pool_path": LEARNWARE_FOLDER_POOL_PATH,
-    "learnware_folder_config": {"yaml_file": "learnware.yaml", "module_file": "__init__.py",},
+    "learnware_folder_config": {
+        "yaml_file": "learnware.yaml",
+        "module_file": "__init__.py",
+    },
     "database_url": f"sqlite:///{DATABASE_PATH}",
     "max_reduced_set_size": 1310720,
     "backend_host": "http://www.lamda.nju.edu.cn/learnware/api",
diff --git a/learnware/learnware/__init__.py b/learnware/learnware/__init__.py
index 70e35d6..a094521 100644
--- a/learnware/learnware/__init__.py
+++ b/learnware/learnware/__init__.py
@@ -31,7 +31,10 @@ def get_learnware_from_dirpath(id: str, semantic_spec: dict, learnware_dirpath:
         The contructed learnware object, return None if build failed
     """
     learnware_config = {
-        "model": {"class_name": "Model", "kwargs": {},},
+        "model": {
+            "class_name": "Model",
+            "kwargs": {},
+        },
         "stat_specifications": [
             {
                 "module_path": "learnware.specification",
diff --git a/learnware/learnware/reuse.py b/learnware/learnware/reuse.py
index 0b68667..b618002 100644
--- a/learnware/learnware/reuse.py
+++ b/learnware/learnware/reuse.py
@@ -302,7 +302,7 @@ class AveragingReuser(BaseReuser):
                 pred_y = pred_y.detach().cpu().numpy()
             if not isinstance(pred_y, np.ndarray):
                 raise TypeError(f"Model output must be np.ndarray or torch.Tensor")
-            
+
             if len(pred_y.shape) == 1:
                 pred_y = pred_y.reshape(-1, 1)
             else:
@@ -312,7 +312,7 @@ class AveragingReuser(BaseReuser):
                 elif self.mode == "vote_by_prob":
                     pred_y = softmax(pred_y, axis=-1)
             preds.append(pred_y)
-        
+
         if self.mode == "vote_by_prob":
             return np.mean(preds, axis=0)
         else:
@@ -325,9 +325,9 @@ class AveragingReuser(BaseReuser):
 
 class EnsemblePruningReuser(BaseReuser):
     """
-        Baseline Multiple Learnware Reuser uing Marign Distribution guided multi-objective evolutionary Ensemble Pruning (MDEP) Method.
-                
-        References: [1] Yu-Chang Wu, Yi-Xiao He, Chao Qian, and Zhi-Hua Zhou. Multi-objective Evolutionary Ensemble Pruning Guided by Margin Distribution. In: Proceedings of the 17th International Conference on Parallel Problem Solving from Nature (PPSN'22), Dortmund, Germany, 2022.
+    Baseline Multiple Learnware Reuser uing Marign Distribution guided multi-objective evolutionary Ensemble Pruning (MDEP) Method.
+
+    References: [1] Yu-Chang Wu, Yi-Xiao He, Chao Qian, and Zhi-Hua Zhou. Multi-objective Evolutionary Ensemble Pruning Guided by Margin Distribution. In: Proceedings of the 17th International Conference on Parallel Problem Solving from Nature (PPSN'22), Dortmund, Germany, 2022.
     """
 
     def __init__(self, learnware_list: List[Learnware], mode: str):
@@ -359,7 +359,7 @@ class EnsemblePruningReuser(BaseReuser):
             - The ground truth of validation set.
             - The dimension is (number of instances, 1).
         maxgen : int
-            - The maximum number of iteration rounds. 
+            - The maximum number of iteration rounds.
 
         Returns
         -------
@@ -443,7 +443,7 @@ class EnsemblePruningReuser(BaseReuser):
             - The ground truth of validation set.
             - The dimension is (number of instances, 1).
         maxgen : int
-            - The maximum number of iteration rounds. 
+            - The maximum number of iteration rounds.
 
         Returns
         -------
@@ -557,7 +557,7 @@ class EnsemblePruningReuser(BaseReuser):
             - The ground truth of validation set.
             - The dimension is (number of instances, 1).
         maxgen : int
-            - The maximum number of iteration rounds. 
+            - The maximum number of iteration rounds.
 
         Returns
         -------
@@ -645,7 +645,7 @@ class EnsemblePruningReuser(BaseReuser):
 
     def _get_predict(self, X: np.ndarray, selected_idxes: List[int]):
         """Concatenate the output of learnwares corresponding to selected_idxes
-        
+
         Parameters
         ----------
         X : np.ndarray
diff --git a/learnware/specification/base.py b/learnware/specification/base.py
index 732ff92..56c1ad9 100644
--- a/learnware/specification/base.py
+++ b/learnware/specification/base.py
@@ -74,7 +74,7 @@ class Specification:
 
     def update_stat_spec(self, *args, **kwargs):
         """Update the statistical specification by the way of 'name'='value'
-             or use class name as default name
+        or use class name as default name
         """
         for _v in args:
             self.stat_spec[_v.__class__.__name__] = _v
diff --git a/learnware/specification/rkme.py b/learnware/specification/rkme.py
index 6f9471a..68c572f 100644
--- a/learnware/specification/rkme.py
+++ b/learnware/specification/rkme.py
@@ -428,7 +428,9 @@ class RKMEStatSpecification(BaseStatSpecification):
         rkme_to_save["beta"] = rkme_to_save["beta"].tolist()
         rkme_to_save["device"] = "gpu" if rkme_to_save["cuda_idx"] != -1 else "cpu"
         json.dump(
-            rkme_to_save, codecs.open(save_path, "w", encoding="utf-8"), separators=(",", ":"),
+            rkme_to_save,
+            codecs.open(save_path, "w", encoding="utf-8"),
+            separators=(",", ":"),
         )
 
     def load(self, filepath: str) -> bool:
@@ -521,7 +523,7 @@ def torch_rbf_kernel(x1, x2, gamma) -> torch.Tensor:
     """
     x1 = x1.double()
     x2 = x2.double()
-    X12norm = torch.sum(x1 ** 2, 1, keepdim=True) - 2 * x1 @ x2.T + torch.sum(x2 ** 2, 1, keepdim=True).T
+    X12norm = torch.sum(x1**2, 1, keepdim=True) - 2 * x1 @ x2.T + torch.sum(x2**2, 1, keepdim=True).T
     return torch.exp(-X12norm * gamma)
 
 
diff --git a/tests/test_learnware_client/test_reuse.py b/tests/test_learnware_client/test_reuse.py
index 699a138..b1659f2 100644
--- a/tests/test_learnware_client/test_reuse.py
+++ b/tests/test_learnware_client/test_reuse.py
@@ -33,7 +33,6 @@ if __name__ == "__main__":
         learnware_list.append(learnware)
 
     with LearnwaresContainer(learnware_list, zip_paths) as env_container:
-
         learnware_list = env_container.get_learnware_list_with_container()
         reuser = AveragingReuser(learnware_list, mode="vote")
         input_array = np.random.randint(0, 3, size=(20, 9))
diff --git a/tests/test_workflow/test_workflow.py b/tests/test_workflow/test_workflow.py
index 403244c..89e71aa 100644
--- a/tests/test_workflow/test_workflow.py
+++ b/tests/test_workflow/test_workflow.py
@@ -19,7 +19,10 @@ curr_root = os.path.dirname(os.path.abspath(__file__))
 
 user_semantic = {
     "Data": {"Values": ["Tabular"], "Type": "Class"},
-    "Task": {"Values": ["Classification"], "Type": "Class",},
+    "Task": {
+        "Values": ["Classification"],
+        "Type": "Class",
+    },
     "Library": {"Values": ["Scikit-learn"], "Type": "Class"},
     "Scenario": {"Values": ["Education"], "Type": "Tag"},
     "Description": {"Values": "", "Type": "String"},