[Python-ideas] Re: A shortcut to load a JSON file into a dict : json.loadf

Sept. 16, 2020

      Is that suggested code? I don't follow.

But if it is, no. personally, I think ANY use of system settings is a bad
idea [*]. But certainly no need to even think about it for JSON.

-CHB

* have we not learned that in the age of the internet the machine the code
happens to be running on has nothing to do with the user of the
applications' needs? Timezones, encodings, number formats, NOTHING.

On Wed, Sep 16, 2020 at 8:45 PM Wes Turner <wes.turner@gmail.com> wrote:
...
Is all of this locale/encoding testing necessary (or even sufficient)?
```python
import json
import locale
import os
def get_default_encoding():
    """
    TODO XXX: ???
    """
    default_encoding = locale.getdefaultlocale()[1]
    if default_encoding.startswith("UTF-"):
        return default_encoding
    else:
        return "UTF-8"
def dumpf(obj, path, *args, **kwargs):
    with open(
        os.fspath(path),
        "w",
        encoding=kwargs.pop("encoding", get_default_encoding()),
    ) as file_:
        return json.dump(obj, file_, *args, **kwargs)
def loadf(path, *args, **kwargs):
    with open(
        os.fspath(path),
        "r",
        encoding=kwargs.pop("encoding", get_default_encoding()),
    ) as file_:
        return json.load(file_, *args, **kwargs)
import pathlib
import unittest
class TestJsonLoadfAndDumpf(unittest.TestCase):
    def setUp(self):
        self.locales = ["", "C", "en_US.UTF-8", "japanese"]
        self.encodings = [None, "UTF-8", "UTF-16", "UTF-32"]
data = dict(
            obj=dict(a=dict(b=[1, 2, 3])),
            encoding=None,
            path=pathlib.Path(".") / "test_loadf_and_dumpf.json",
        )
        if os.path.isfile(data["path"]):
            os.unlink(data["path"])
        self.data = data
self.previous_locale = locale.getlocale()
def tearDown(self):
        locale.setlocale(locale.LC_ALL, self.previous_locale)
def test_get_default_encoding(self):
        for localestr in self.locales:
            locale.setlocale(locale.LC_ALL, localestr)
            output = get_default_encoding()
            assert output.startswith("UTF-")
def test_dumpf_and_loadf(self):
        data = self.data
        for localestr in self.locales:
            locale.setlocale(locale.LC_ALL, localestr)
            for encoding in self.encodings:
                dumpf_output = dumpf(
                    data["obj"], data["path"], encoding=encoding
                )
                loadf_output = loadf(data["path"], encoding=encoding)
                assert loadf_output == data["obj"]
```
On Wed, Sep 16, 2020 at 8:30 PM Christopher Barker <pythonchb@gmail.com>
wrote:
...
On Wed, Sep 16, 2020 at 2:53 PM Wes Turner <wes.turner@gmail.com> wrote:
...
So I was not correct: dump does not default to UTF-8 (and does not
accept an encoding= parameter)
...
I think dumpf() should use UTF-8, and that's it. If anyone really wants
something else, they can get it by providing an open text file object.
Why would we impose UTF-8 when the spec says UTF-8, UTF-16, or UTF-32?
The idea was that the encoding was one of the motivators to doing this in
the first place. But I suppose as long as utf-8 is the default, and only
the three "official" ones are allowed, then yeah, we could add an encoding
keyword argument.
-CHB
--
Christopher Barker, PhD
Python Language Consulting
  - Teaching
  - Scientific Software Development
  - Desktop GUI and Web Development
  - wxPython, numpy, scipy, Cython
-- 
Christopher Barker, PhD

Python Language Consulting
  - Teaching
  - Scientific Software Development
  - Desktop GUI and Web Development
  - wxPython, numpy, scipy, Cython