How to dump json without quotes in python

Question

Here is how I dump a file

with open('es_hosts.json', 'w') as fp:
  json.dump(','.join(host_list.keys()), fp)

The results is

 "a,b,c"

I would like:

 a,b,c

Thanks

Answer 1

To remove the quotation marks in the keys only, which may be important if you are parsing it later (presumably with some tolerant parser or maybe you just pipe it directly into node for bizarre reasons), you could try the following regex.

re.sub(r'(?<!: )"(\S*?)"', '\\1', json_string)

One issue is that this regex expects fields to be seperated key: value and it will fail for key:value. You could make it work for the latter with a minor change, but similarly it won't work for variable amounts of whitespace after :

There may be other edge cases but it will work with outputs of json.dumps, however the results will not be parseable by json. Some more tolerant parsers like yaml might be able to read the results.

import re
regex = r'(?<!: )"(\S*?)"'
o = {"noquotes" : 127, "put quotes here" : "and here", "but_not" : "there"}
s = json.dumps(o)
s2 = json.dumps(o, indent=3)
strip_s = re.sub(regex,'\\1',s)
strip_s2 = re.sub(regex,'\\1',s2)

print(strip_s)
print(strip_s2)

assert(json.loads(strip_s) == json.loads(s) == json.loads(strip_s2) == json.loads(s2) == object)

Will raise a ValueError but prints what you want.

Answer 2

Before doing a string replace, you might want to strip the quotation marks:

print '"a,b,c"'.strip('"')

Output:

a,b,c

That's closer to what you want to achieve. Even just removing the first and the last character works: '"a,b,c"'[1:-1].

But have you looked into this question?