reStructuredText not respecting subheadings

Question

Here's a simple reST snippet:

deleting this line causes all subheadings to be rendered as h1 tags

I should be an h1
=================

I should be an h2
-----------------
foo            

I should also be an h2
----------------------
foo

and here's a demonstration of it being rendered:

with initial line: http://rst.ninjs.org/?n=ff67380d732a33c7844f350c240804d0
without initial line: http://rst.ninjs.org/?n=550ea2c1b4233affdce1d158c5dc4d99

I'm rendering reST using the following Python:

from docutils.core import publish_parts
parts = publish_parts(rest_content, writer_name="html")
html_snippet = parts['html_body']

How do I get subheadings (specifically, <h2> tags) without the initial line? Do have provide two levels of hierarchy above the subheadings? Naively providing a page header doesn't help: http://rst.ninjs.org/?n=e874f6eaad17c8ae7fd565f9ecb2212b

Answer 1

Don't promote the 1st title to document title.

Note the settings_overrides param passed to publish_parts() in the example below:

rest_content = """
I should be an h1
=================

I should be an h2
-----------------
foo


I should also be an h2
----------------------
foo
"""

from docutils.core import publish_parts
parts = publish_parts(rest_content, writer_name="html",
        settings_overrides={'doctitle_xform':False})
html_snippet = parts['html_body']

print(html_snippet)

And the output:

<div class="document">
<div class="section" id="i-should-be-an-h1">
<h1>I should be an h1</h1>
<div class="section" id="i-should-be-an-h2">
<h2>I should be an h2</h2>
<p>foo</p>
</div>
<div class="section" id="i-should-also-be-an-h2">
<h2>I should also be an h2</h2>
<p>foo</p>
</div>
</div>
</div>