How to add a Sectional Break in word using python-docx

I have been trying to add a sectional break into my word document using python-docx. I basically want to add a sectional break before every paragraph having style = "heading 1". I have written the following code. The code goes as follows:

1)get the total number of paragraphs

2)find the index of the paragraph with style = "heading 1"

3)add a run to the paragraph which is before the paragraph having style = "heading 1"

4)add a sectional break to the run

z=len(doc.paragraphs)
for i in range(0,z):

    if doc.paragraphs[i].style.name == "Heading 1":
        run_new=doc.paragraphs[i-1].add_run()
        run_new.add_break(docx.enum.text.WD_BREAK.SECTION_NEXT_PAGE)

But it gives me this error.

Traceback (most recent call last):
  File "D:/Pycharm Projects/pydocx/trial4.py", line 8, in <module>
    run_new.add_break(docx.enum.text.WD_BREAK.SECTION_NEXT_PAGE)
  File "D:\Pycharm Projects\pydocx\env\lib\site-packages\docx\text\run.py", line 42, in add_break
    }[break_type]
KeyError: 2

How should I add the sectional break?

Solution

python-docx currently has no API support for inserting a section break at an arbitrary location. You can only add a new section at the end of the document, typically in the course of generating a new document from the top down to the bottom.

>>> new_section = document.add_section(WD_SECTION.ODD_PAGE)
>>> new_section.start_type
ODD_PAGE (4)

There is more on adding a section on the documentation page here:
https://python-docx.readthedocs.io/en/latest/user/sections.html