[python mode] Handle continued lines better

Closes codemirror#5256

Author: marijnh

mode/python/python.js

@@ -41,7 +41,7 @@
   CodeMirror.defineMode("python", function(conf, parserConf) {
     var ERRORCLASS = "error";
 
-    var delimiters = parserConf.delimiters || parserConf.singleDelimiters || /^[\(\)\[\]\{\}@,:`=;\.]/;
+    var delimiters = parserConf.delimiters || parserConf.singleDelimiters || /^[\(\)\[\]\{\}@,:`=;\.\\]/;
     //               (Backwards-compatiblity with old, cumbersome config system)
     var operators = [parserConf.singleOperators, parserConf.doubleOperators, parserConf.doubleDelimiters, parserConf.tripleDelimiters,
                      parserConf.operators || /^([-+*/%\/&|^]=?|[<>=]+|\/\/=?|\*\*=?|!=|[~!@])/]
@@ -76,9 +76,10 @@
 
     // tokenizers
     function tokenBase(stream, state) {
-      if (stream.sol()) state.indent = stream.indentation()
+      var sol = stream.sol() && state.lastToken != "\\"
+      if (sol) state.indent = stream.indentation()
       // Handle scope changes
-      if (stream.sol() && top(state).type == "py") {
+      if (sol && top(state).type == "py") {
         var scopeOffset = top(state).offset;
         if (stream.eatSpace()) {
           var lineOffset = stream.indentation();
@@ -100,13 +101,8 @@
     function tokenBaseInner(stream, state) {
       if (stream.eatSpace()) return null;
 
-      var ch = stream.peek();
-
       // Handle Comments
-      if (ch == "#") {
-        stream.skipToEnd();
-        return "comment";
-      }
+      if (stream.match(/^#.*/)) return "comment";
 
       // Handle Number Literals
       if (stream.match(/^[0-9\.]/, false)) {