CODEWITHSUNDEEP
pythonjsonlinuxpython-3.xcarriage-return
jef
jef

Reputation: 4083

How to explicitly set carriage return when doing json.dump?

My python script generates json file. And I have to support this python file working on windows and linux. The problem is a difference carriage return on windows and linux. When I run this code on windows, it outputs CRLF json. And it outputs LF json when I run this on linux.

So how to explicitly set carriage return when doing json dump in python3.5? I couln

import json
fpath = "hoge.json"
data = {"AGE": 12, "HOGE": [{"GUA": 3}]}
with open(fpath, 'wt', encoding="utf-8") as outfile:
    json.dump(data, outfile, indent=4, sort_keys=True, ensure_ascii=False)

http://docs.python.jp/3/library/json.html

Upvotes: 10

Views: 13760

Answers (2)

thebjorn
thebjorn

Reputation: 27360

Line endings are white space in the Json spec (https://www.rfc-editor.org/rfc/rfc7159 section 2 at the bottom):

Insignificant whitespace is allowed before or after any of the six structural characters.

  ws = *(
          %x20 /              ; Space
          %x09 /              ; Horizontal tab
          %x0A /              ; Line feed or New line
          %x0D )              ; Carriage return

This means that every reader must handle both CR and LF to be conformant.

Upvotes: 2

ShadowRanger
ShadowRanger

Reputation: 155734

If you insist on consistent CRLF behavior (the JSON spec requires parsers to handle both, but opening it in certain plain text readers like Notepad might be easier with consistent CRLF), the solution is in the open function, not the json module.

Just pass newline='\r\n' to open, and it will translate any \n written by json to \r\n seamlessly on all systems, rather than the default behavior of translating to os.linesep (which is \r\n on Windows and \n on most other OSes):

with open(fpath, 'w', encoding="utf-8", newline='\r\n') as outfile:
    json.dump(data, outfile, indent=4, sort_keys=True, ensure_ascii=False)

Upvotes: 15

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