优化文件大小获取失败时，直接返回0

pt_site/UtilityTool.py

@@ -57,6 +57,8 @@ class FileSizeConvert:
 
     @staticmethod
     def parse_2_byte(file_size: str):
+        if not file_size:
+            return 0
         """将文件大小字符串解析为字节"""
         regex = re.compile(r'(\d+(?:\.\d+)?)\s*([kmgtp]?b)', re.IGNORECASE)
 
@@ -67,11 +69,13 @@ class FileSizeConvert:
 
     @staticmethod
     def parse_2_file_size(byte: int):
+        if not byte:
+            return '0B'
         units = ["B", "KB", "MB", "GB", "TB", "PB", 'EB']
         size = 1024.0
         for i in range(len(units)):
             if (byte / size) < 1:
-                return "%.3f%s" % (byte, units[i])
+                return "%.3f %s" % (byte, units[i])
             byte = byte / size