DOCX (Microsoft Word)

A .docx is a ZIP of XML parts. Body text lives in word/document.xml. Two tiers:

• Default — python-docx (preinstalled): create, read, and simple edits. Use for almost everything.
• Advanced — raw OOXML via zipfile: only for what python-docx cannot express — tracked changes (redlines), comments, and exact-fidelity edits that must preserve every untouched byte. See [Raw OOXML](#raw-ooxml-advanced).

Runtime

Use exec with complete Python source (language: python). python-docx is

preinstalled. Prefer creating, saving, reopening, and validating the deliverable

in one call; later calls can revise the same relative filename. Follow the

turn's User workspace instructions for locating inputs, output boundaries,

and presenting the finished file. When editing, write a new output unless the

user explicitly requested an authorized replacement.

Read / extract

from docx import Document

doc = Document("in.docx")
text = "\n".join(p.text for p in doc.paragraphs)  # body paragraphs
for tbl in doc.tables:  # tables
    for row in tbl.rows:
        print([c.text for c in row.cells])

doc.paragraphs skips text inside tables, headers/footers, and text boxes — iterate doc.tables and doc.sections[i].header/.footer for those. Each paragraph's style: p.style.name (e.g. "Heading 1").

To read tracked changes, parse the XML directly — python-docx ignores <w:ins>/<w:del>:

import zipfile, re

xml = zipfile.ZipFile("in.docx").read("word/document.xml").decode("utf-8")
# inserted text = <w:ins>…<w:t>…  deleted = <w:del>…<w:delText>…
print(re.findall(r"<w:t[^>]*>(.*?)</w:t>", xml))

Create

from docx import Document
from docx.shared import Pt, Inches, RGBColor
from docx.enum.text import WD_ALIGN_PARAGRAPH

doc = Document()  # default template page size
doc.add_heading("Quarterly Report", level=0)  # 0 = title; 1..9 = H1..H9
p = doc.add_paragraph("Intro paragraph. ")
run = p.add_run("Bold tail.")
run.bold = True
doc.add_paragraph("First item", style="List Bullet")  # real list style, never a "• " literal
doc.add_paragraph("Step one", style="List Number")

# Table — header row + data
tbl = doc.add_table(rows=1, cols=2)
tbl.style = "Light Grid Accent 1"
tbl.rows[0].cells[0].text, tbl.rows[0].cells[1].text = "Metric", "Value"
for k, v in [("Revenue", "1.2M"), ("Growth", "15%")]:
    c = tbl.add_row().cells
    c[0].text, c[1].text = k, v

doc.add_picture("chart.png", width=Inches(5))  # image, scaled to width
doc.add_page_break()
doc.save("out.docx")

# Validate immediately; later exec calls can also reopen this relative path.
check = Document("out.docx")
assert check.paragraphs, "generated DOCX has no paragraphs"
import zipfile

with zipfile.ZipFile("out.docx") as package:
    assert package.testzip() is None, "generated DOCX has a corrupt ZIP member"

Rules:

• Never type bullet/number characters (•, 1.) into text — use style="List Bullet"/"List Number". Only list styles defined in the doc's template are available.
• No \n inside a run — each visual line is its own add_paragraph.
• Built-in style names must match the template (e.g. "Heading 1", "List Bullet"); a wrong name raises KeyError.
• Units: Pt, Inches, Cm from docx.shared. Colors: RGBColor(0x1F,0x4E,0x79).

Page setup, headers/footers, page numbers

from docx.shared import Inches

sec = doc.sections[0]
sec.page_width, sec.page_height = Inches(8.5), Inches(11)  # Letter
sec.top_margin = sec.bottom_margin = Inches(1)
sec.header.paragraphs[0].text = "Confidential"

Page-number fields aren't in the python-docx API; inject the field XML into a footer run:

from docx.oxml.ns import qn
from docx.oxml import OxmlElement


def add_page_number(paragraph):
    for t in ("begin", "instr", "end"):
        r = OxmlElement("w:r")
        if t == "instr":
            fld = OxmlElement("w:instrText")
            fld.set(qn("xml:space"), "preserve")
            fld.text = "PAGE"
        else:
            fld = OxmlElement("w:fldChar")
            fld.set(qn("w:fldCharType"), t)
        r.append(fld)
        paragraph._p.append(r)


add_page_number(doc.sections[0].footer.paragraphs[0])

A clickable Table of Contents is also a field; Word shows "right-click → Update Field" until refreshed. Same pattern with instrText = TOC \o "1-3" \h \z \u.

Edit existing (simple)

python-docx preserves the rest of the document; mutate then save under a new name.

doc = Document("in.docx")
# Find-and-replace, keeping each run's formatting:
for p in doc.paragraphs:
    if "{{CLIENT}}" in p.text:
        for r in p.runs:
            r.text = r.text.replace("{{CLIENT}}", "Acme Co")
doc.save("out.docx")

Gotcha: Word splits text across runs, so a phrase may not live in one run.text even though p.text shows it whole. If the placeholder spans runs, set p.runs[0].text = p.text.replace(...) and clear the rest (for r in p.runs[1:]: r.text = "") — this collapses formatting to the first run, acceptable for plain placeholders. For exact-fidelity edits, use the raw-OOXML tier.

.doc → .docx and PDF export (LibreOffice, optional)

Legacy binary .doc can't be read by python-docx, and there is no built-in PDF

export. Both need LibreOffice, which is optional and often absent. Only use

it from exec; locate it with shutil.which("soffice"), keep its

profile/conversion directory relative to the stable working directory, and clean

conversion intermediates when finished. Never search for a desktop installation

by absolute path and never write conversion files to /tmp. If it is absent,

degrade with a clear note.

import shutil

soffice = shutil.which("soffice")
if soffice is None:
    print("soffice unavailable — ask the user for .docx or omit PDF export")
# If present, invoke it with subprocess.run([...], check=True) here, using only
# relative paths below this run directory, then validate the result immediately.

Never fetch or install authoring dependencies during a document task. If a

declared runtime dependency is absent, report an incomplete deployment and stop.

Raw OOXML (advanced)

Only when python-docx can't express it: tracked changes, comments, exact-fidelity edits. Workflow: read the XML part → edit it as text → re-zip every original member, rewriting only the changed part.

import zipfile

src, dst = "in.docx", "out.docx"
with zipfile.ZipFile(src) as z:
    xml = z.read("word/document.xml").decode("utf-8")
xml = xml.replace("OLD", "NEW")  # or splice tracked-change elements (below)
with zipfile.ZipFile(src) as zin, zipfile.ZipFile(dst, "w", zipfile.ZIP_DEFLATED) as zout:
    for item in zin.infolist():
        data = (
            xml.encode("utf-8") if item.filename == "word/document.xml" else zin.read(item.filename)
        )
        zout.writestr(item, data)

Critical traps (these silently corrupt the file or lose text):

• xml:space="preserve" on any <w:t>/<w:delText> with leading/trailing whitespace, or Word strips the space.
• Don't pretty-print into text nodes — added newlines/indent inside <w:t> become visible spaces. Edit the XML as a string; never reserialize the whole tree with indentation.
• Keep parts consistent: new image/part → add its <Relationship> in word/_rels/document.xml.rels and a content type in [Content_Types].xml, or the doc opens "corrupt."
• Unique IDs: every w:id on <w:ins>/<w:del>/comments must be unique in the file. w14:paraId/w16cid:durableId must be < 0x7FFFFFFF (8-digit hex).
• Element order in <w:pPr>: pStyle, numPr, spacing, ind, jc, then rPr last.

Tracked changes (redlines)

Use a consistent author (default "Claude" unless the user names one) and ISO date. Replace the whole <w:r> with siblings — never nest change tags inside a run — and copy the original <w:rPr> into the new runs to keep formatting.

<!-- change "30 days" → "60 days" -->
<w:r><w:t xml:space="preserve">The term is </w:t></w:r>
<w:del w:id="1" w:author="Claude" w:date="2026-01-01T00:00:00Z">
  <w:r><w:delText>30</w:delText></w:r></w:del>
<w:ins w:id="2" w:author="Claude" w:date="2026-01-01T00:00:00Z">
  <w:r><w:t>60</w:t></w:r></w:ins>
<w:r><w:t xml:space="preserve"> days.</w:t></w:r>

• Inside <w:del> use <w:delText> (not <w:t>); inside <w:ins> never use <w:delText>.
• Deleting a whole paragraph: also mark its paragraph mark — add <w:del .../> inside <w:pPr><w:rPr> — or accepting changes leaves an empty paragraph.
• Reject another author's insertion: nest your <w:del> inside their <w:ins>. Restore their deletion: add a new <w:ins> after their <w:del> — never edit their tags.

Comments

Comments live in a separate word/comments.xml part (create it + its relationship in word/_rels/document.xml.rels + a content-type override if absent). In document.xml, the anchor markers <w:commentRangeStart w:id="N"/> and <w:commentRangeEnd w:id="N"/> are siblings of <w:r>, never inside one; follow the end marker with <w:r><w:rPr><w:rStyle w:val="CommentReference"/></w:rPr><w:commentReference w:id="N"/></w:r>. This is fiddly — verify the output opens in Word.

Verify before returning

Always confirm the file reopens cleanly — a silent corruption is the most common failure:

from docx import Document

d = Document("out.docx")
print(len(d.paragraphs), "paragraphs OK")

For raw-OOXML edits, run zipfile.ZipFile('out.docx').testzip() and

well-formedness-check each edited XML part with lxml.etree.parse in the same

exec Python call that saves out.docx.