Unable to parse TAB in JSON files

Question

I am running into a parsing problem when loading JSON files that seem to have the TAB character in them.

When I go to http://jsonlint.com/, and I enter the part with the TAB character:

{     "My_String": "Foo bar.  Bar foo." } 

The validator complains with:

Parse error on line 2: {    "My_String": "Foo bar. Bar foo." ------------------^ Expecting 'STRING', 'NUMBER', 'NULL', 'TRUE', 'FALSE', '{', '[' 

This is literally a copy/paste of the offending JSON text.

I have tried loading this file with json and simplejson without success. How can I load this properly? Should I just pre-process the file and replace TAB by \t or by a space? Or is there anything that I am missing here?

Update:

Here is also a problematic example in simplejson:

foo = '{"My_string": "Foo bar.\t Bar foo."}' simplejson.loads(foo)  JSONDecodeError: Invalid control character '\t' at: line 1 column 24 (char 23) 

Answer 1

From JSON standard:

Insignificant whitespace is allowed before or after any token. The whitespace characters are: character tabulation (U+0009), line feed (U+000A), carriage return (U+000D), and space (U+0020). Whitespace is not allowed within any token, except that space is allowed in strings.

It means that a literal tab character is not allowed inside a JSON string. You need to escape it as \t (in a .json-file):

{"My_string": "Foo bar.\t Bar foo."} 

In addition if json text is provided inside a Python string literal then you need double escape the tab:

foo = '{"My_string": "Foo bar.\\t Bar foo."}' # in a Python source 

Or use a Python raw string literal:

foo = r'{"My_string": "Foo bar.\t Bar foo."}' # in a Python source