update regexes to match django

src/grammar.json

@@ -138,7 +138,7 @@
     },
     "number": {
       "type": "PATTERN",
-      "value": "[-+]?(?:[0-9]+(?:\\.[0-9]*)?|\\.[0-9]+)(?:[eE][0-9]+)?"
+      "value": "[-+]?(?:[0-9](?:_?[0-9])*(?:\\.(?:[0-9](?:_?[0-9])*)?)?|\\.[0-9](?:_?[0-9])*)(?:[eE][0-9](?:_?[0-9])*)?"
     },
     "string": {
       "type": "PATTERN",
@@ -146,7 +146,7 @@
     },
     "attribute": {
       "type": "PATTERN",
-      "value": "[a-zA-Z0-9_]+(?:\\.[a-zA-Z0-9_]+)*"
+      "value": "[a-zA-Z0-9][a-zA-Z0-9_]*(?:\\.[a-zA-Z0-9][a-zA-Z0-9_]*)*"
     },
     "variable_attribute": {
       "type": "SEQ",