Fix the pull_asset code; Update minor docstring (#516)

* Fix the asset remove code; Update minor docstring

* fix bug

metadrive/pull_asset.py

@@ -1,10 +1,10 @@
 import argparse
 import os
+import progressbar
 import shutil
 import urllib.request
 import zipfile
-
-import progressbar
+import filelock
 
 from metadrive.constants import VERSION
 from metadrive.engine.logger import get_logger
@@ -55,17 +55,21 @@ def pull_asset(update):
                 return
 
     zip_path = os.path.join(TARGET_DIR, 'assets.zip')
+    zip_lock = os.path.join(TARGET_DIR, 'assets.zip.lock')
 
     # Fetch the zip file
     logger.info("Pull assets from {}".format(ASSET_URL))
     urllib.request.urlretrieve(ASSET_URL, zip_path, MyProgressBar())
 
     # Extract the zip file to the desired location
-    with zipfile.ZipFile(zip_path, 'r') as zip_ref:
-        zip_ref.extractall(TARGET_DIR)
+    lock = filelock.FileLock(zip_lock)
+    with lock:
+        with zipfile.ZipFile(zip_path, 'r') as zip_ref:
+            zip_ref.extractall(TARGET_DIR)
 
     # Remove the downloaded zip file (optional)
-    os.remove(zip_path)
+    if os.path.exists(zip_path):
+        os.remove(zip_path)
     logger.info("Successfully download assets, version: {}. MetaDrive version: {}".format(asset_version(), VERSION))
 
 

metadrive/scenario/utils.py

@@ -5,7 +5,6 @@
 import matplotlib.pyplot as plt
 import numpy as np
 from matplotlib.pyplot import figure
-
 from metadrive.component.static_object.traffic_object import TrafficCone, TrafficBarrier
 from metadrive.component.traffic_light.base_traffic_light import BaseTrafficLight
 from metadrive.component.traffic_participants.cyclist import Cyclist
@@ -323,6 +322,14 @@ def convert_recorded_scenario_exported(record_episode, scenario_log_interval=0.1
 
 
 def read_scenario_data(file_path):
+    """Read a scenario pkl file and return the Scenario Description instance.
+
+    Args:
+        file_path: the path to a scenario file (usually ends with `.pkl`).
+
+    Returns:
+        The Scenario Description instance of that scenario.
+    """
     assert SD.is_scenario_file(file_path), "File: {} is not scenario file".format(file_path)
     with open(file_path, "rb") as f:
         # unpickler = CustomUnpickler(f)
@@ -333,11 +340,21 @@ def read_scenario_data(file_path):
 
 def read_dataset_summary(file_folder, check_file_existence=True):
     """
-    We now support two methods to load pickle files.
+    Read the `dataset_summary.pkl` and return the metadata of each scenario in this dataset.
+
+    This function supports two methods to load pickle files. The first is the old method where we store pickle files in
+    0.pkl, 1.pkl, .... The second is the new method which use a summary file to record important metadata of
+    each scenario.
 
-    The first is the old method where we store pickle files in 0.pkl, 1.pkl, ...
+    Args:
+        file_folder: the path to the root folder of your dataset.
+        check_file_existence: check if all scenarios registered in the summary file exist.
 
-    The second is the new method which use a summary file to record important metadata of each scenario.
+    Returns:
+        A tuple of three elements:
+        1) the summary dict mapping from scenario ID to its metadata,
+        2) the list of all scenarios IDs, and
+        3) a dict mapping from scenario IDs to the folder that hosts their files.
     """
     summary_file = os.path.join(file_folder, SD.DATASET.SUMMARY_FILE)
     mapping_file = os.path.join(file_folder, SD.DATASET.MAPPING_FILE)

setup.py

@@ -59,7 +59,8 @@ def is_win():
     "scipy",
     "psutil",
     "geopandas",
-    "shapely"
+    "shapely",
+    "filelock"
 ]
 
 nuplan_requirement = [