QJsonDocument fails with a confusing error

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Dear developers,

Consider the following piece of code:

from PyQt5.QtCore import QJsonDocument

json =3D {
    "catalog": [
        {
            "version": None,
        },
    ]}QJsonDocument(json)

Under Python 3.6+ and PyQt514+ (haven't checked other versions), it results
in the following error at the last line:

TypeError: a value has type 'list' but 'QJsonValue' is expected

QJsonDocument clearly supports lists: QJsonDocument({'a': []}) works fine.

As it turns out, the None value is the reason. Although the docs
<https://doc.qt.io/qt-5/qjsondocument.html#JsonFormat-enum> clearly show
that QJsonDocument supports null values, None is not supported in
PyQt5: QJsonDocument({'a':
None}) results in

TypeError: a value has type 'NoneType' but 'QJsonValue' is expected.

Is it a bug that None is not translated as null? If not, the error message
should be more informative, at least.

Best regards,

Anton
=F0=9F=8D=8F

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<div dir=3D"ltr"><p>Dear developers,<br></p><p>Consider the following piece=
 of code:</p>

<pre><code><span>from</span><span> </span><span>PyQt5</span><span>.</span><=
span>QtCore</span><span> </span><span>import</span><span> </span><span>QJso=
nDocument</span><span>

json </span><span>=3D</span><span> </span><span>{</span><span>
    </span><span>&quot;catalog&quot;</span><span>:</span><span> </span><spa=
n>[</span><span>
        </span><span>{</span><span>
            </span><span>&quot;version&quot;</span><span>:</span><span> </s=
pan><span>None</span><span>,</span><span>
        </span><span>},</span><span>
    </span><span>]</span><span>
</span><span>}</span><span>
</span><span>QJsonDocument</span><span>(</span><span>json</span><span>)</sp=
an></code></pre>

<p>Under Python 3.6+ and PyQt514+ (haven&#39;t checked other versions), it =
results in the following error at the last line:</p>

<p><code>TypeError: a value has type &#39;list&#39; but &#39;QJsonValue&#39=
; is expected</code></p>

<p><code>QJsonDocument</code> clearly supports lists: <code>QJsonDocument({=
&#39;a&#39;: []})</code> works fine.</p><p>As it turns out, the <code>None<=
/code> value is the reason. Although the <a href=3D"https://doc.qt.io/qt-5/=
qjsondocument.html#JsonFormat-enum" rel=3D"nofollow noreferrer" target=3D"_=
blank">docs</a> clearly show that <code>QJsonDocument</code> supports <code=
>null</code> values, <code>None</code> is not supported in PyQt5: <code>QJs=
onDocument({&#39;a&#39;: None})</code> results in</p>

<p><code>TypeError: a value has type &#39;NoneType&#39; but &#39;QJsonValue=
&#39; is expected</code>.</p><p>Is it a bug that <span style=3D"font-family=
:monospace">None</span> is not translated as <span style=3D"font-family:mon=
ospace">null</span>? If not, the error message should be more informative, =
at least.<br></p><p>Best regards,</p><p>Anton</p><div><div dir=3D"ltr" clas=
s=3D"gmail_signature" data-smartmail=3D"gmail_signature"><div dir=3D"ltr"><=
div><div dir=3D"ltr"><div><div dir=3D"ltr"><font size=3D"6">=F0=9F=8D=8F</f=
ont><br></div></div></div></div></div></div></div></div>

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