Issue #2: Labelbox seems to timeout, make script re-runnable.

labelboxutils/ui/labelbox_export_json_app.py

@@ -23,6 +23,11 @@ def run_labelbox_json_export(json_file, output_dir, output_format):
     with open(json_file) as file:
         data = file.read()
         decoded_data = json.loads(data)
+
+        six.print_("There are:"
+                   + str(len(decoded_data))
+                   + " samples to download.")
+
         for sample in decoded_data:
             dataset_name = sample['Dataset Name']
             external_id = sample['External ID']
@@ -40,24 +45,36 @@ def run_labelbox_json_export(json_file, output_dir, output_format):
                 file_name = os.path.join(dir_name,
                                          filename_no_extension
                                          + '_' + value + '.bmp')
-                six.print_("writing to:" + file_name)
-
-                urllib.request.urlretrieve(instance_uri, file_name)
-
-                if output_format == 'grey':
-                    image = cv2.imread(file_name)
-                    grey = cv2.cvtColor(image, cv2.COLOR_BGRA2GRAY)
-                    file_name = os.path.join(dir_name,
-                                             filename_no_extension
-                                             + '_' + value + '.png')
-                    cv2.imwrite(file_name, grey)
-                    six.print_("writing to:" + file_name)
-
-                elif output_format == 'rgb':
-                    image = cv2.imread(file_name)
-                    rgb = cv2.cvtColor(image, cv2.COLOR_BGRA2BGR)
-                    file_name = os.path.join(dir_name,
-                                             filename_no_extension
-                                             + '_' + value + '.png')
-                    cv2.imwrite(file_name, rgb)
-                    six.print_("writing to:" + file_name)
+
+                if not os.path.exists(file_name):
+                    six.print_("downloading to:" + file_name)
+                    urllib.request.urlretrieve(instance_uri, file_name)
+
+                if not os.path.exists(file_name):
+                    six.print_("ERROR: Failed to download:" + file_name)
+                else:
+                    if output_format == 'grey':
+
+                        file_name = os.path.join(dir_name,
+                                                 filename_no_extension
+                                                 + '_' + value + '.png')
+
+                        if not os.path.exists(file_name):
+                            image = cv2.imread(file_name)
+                            grey = cv2.cvtColor(image, cv2.COLOR_BGRA2GRAY)
+                            cv2.imwrite(file_name, grey)
+                            six.print_("writing to:" + file_name)
+
+                    elif output_format == 'rgb':
+
+                        file_name = os.path.join(dir_name,
+                                                 filename_no_extension
+                                                 + '_' + value + '.png')
+
+                        if not os.path.exists(file_name):
+                            image = cv2.imread(file_name)
+                            rgb = cv2.cvtColor(image, cv2.COLOR_BGRA2BGR)
+                            cv2.imwrite(file_name, rgb)
+                            six.print_("writing to:" + file_name)
+
+        six.print_("Done")