feat: render math equations in .docx documents (#1160)

* feat: math equation rendering in .docx files
* fix: import fix on .docx pre processing
* test: add test cases for docx equation rendering
* docs: add ThirdPartyNotices.md
* refactor: reformatted with black

packages/markitdown/ThirdPartyNotices.md

@@ -0,0 +1,232 @@
+# THIRD-PARTY SOFTWARE NOTICES AND INFORMATION
+
+**Do Not Translate or Localize**
+
+This project incorporates components from the projects listed below. The original copyright notices and the licenses 
+under which MarkItDown received such components are set forth below. MarkItDown reserves all rights not expressly 
+granted herein, whether by implication, estoppel or otherwise.
+
+1.dwml (https://github.com/xiilei/dwml)
+
+dwml NOTICES AND INFORMATION BEGIN HERE
+
+-----------------------------------------
+
+NOTE 1: What follows is a verbatim copy of dwml's LICENSE file, as it appeared on March 28th, 2025 - including 
+placeholders for the copyright owner and year.
+
+NOTE 2: The Apache License, Version 2.0, requires that modifications to the dwml source code be documented.  
+The following section summarizes these changes. The full details are available in the MarkItDown source code 
+repository under PR #1160 (https://github.com/microsoft/markitdown/pull/1160)
+
+This project incorporates `dwml/latex_dict.py` and `dwml/omml.py` files without any additional logic modifications (which 
+lives in `packages/markitdown/src/markitdown/converter_utils/docx/math` location). However, we have reformatted the code
+according to `black` code formatter.  From `tests/docx.py` file, we have used `DOCXML_ROOT` XML namespaces and the rest of 
+the file is not used.
+
+-----------------------------------------
+
+Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
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+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
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+      separable from, or merely link (or bind by name) to the interfaces of,
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+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
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+      (c) You must retain, in the Source form of any Derivative Works
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+      (d) If the Work includes a "NOTICE" text file as part of its
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+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
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+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
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+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "{}"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright {yyyy} {name of copyright owner}
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+
+-----------------------------------------
+END OF dwml NOTICES AND INFORMATION

packages/markitdown/pyproject.toml

@@ -38,6 +38,7 @@ all = [
   "pandas",
   "openpyxl",
   "xlrd",
+  "lxml",
   "pdfminer.six",
   "olefile",
   "pydub",
@@ -47,7 +48,7 @@ all = [
   "azure-identity"
 ]
 pptx = ["python-pptx"]
-docx = ["mammoth"]
+docx = ["mammoth", "lxml"]
 xlsx = ["pandas", "openpyxl"]
 xls = ["pandas", "xlrd"]
 pdf = ["pdfminer.six"]

packages/markitdown/src/markitdown/converter_utils/docx/math/latex_dict.py

@@ -0,0 +1,273 @@
+# -*- coding: utf-8 -*-
+
+"""
+Adapted from https://github.com/xiilei/dwml/blob/master/dwml/latex_dict.py
+On 25/03/2025
+"""
+
+from __future__ import unicode_literals
+
+CHARS = ("{", "}", "_", "^", "#", "&", "$", "%", "~")
+
+BLANK = ""
+BACKSLASH = "\\"
+ALN = "&"
+
+CHR = {
+    # Unicode : Latex Math Symbols
+    # Top accents
+    "\u0300": "\\grave{{{0}}}",
+    "\u0301": "\\acute{{{0}}}",
+    "\u0302": "\\hat{{{0}}}",
+    "\u0303": "\\tilde{{{0}}}",
+    "\u0304": "\\bar{{{0}}}",
+    "\u0305": "\\overbar{{{0}}}",
+    "\u0306": "\\breve{{{0}}}",
+    "\u0307": "\\dot{{{0}}}",
+    "\u0308": "\\ddot{{{0}}}",
+    "\u0309": "\\ovhook{{{0}}}",
+    "\u030a": "\\ocirc{{{0}}}}",
+    "\u030c": "\\check{{{0}}}}",
+    "\u0310": "\\candra{{{0}}}",
+    "\u0312": "\\oturnedcomma{{{0}}}",
+    "\u0315": "\\ocommatopright{{{0}}}",
+    "\u031a": "\\droang{{{0}}}",
+    "\u0338": "\\not{{{0}}}",
+    "\u20d0": "\\leftharpoonaccent{{{0}}}",
+    "\u20d1": "\\rightharpoonaccent{{{0}}}",
+    "\u20d2": "\\vertoverlay{{{0}}}",
+    "\u20d6": "\\overleftarrow{{{0}}}",
+    "\u20d7": "\\vec{{{0}}}",
+    "\u20db": "\\dddot{{{0}}}",
+    "\u20dc": "\\ddddot{{{0}}}",
+    "\u20e1": "\\overleftrightarrow{{{0}}}",
+    "\u20e7": "\\annuity{{{0}}}",
+    "\u20e9": "\\widebridgeabove{{{0}}}",
+    "\u20f0": "\\asteraccent{{{0}}}",
+    # Bottom accents
+    "\u0330": "\\wideutilde{{{0}}}",
+    "\u0331": "\\underbar{{{0}}}",
+    "\u20e8": "\\threeunderdot{{{0}}}",
+    "\u20ec": "\\underrightharpoondown{{{0}}}",
+    "\u20ed": "\\underleftharpoondown{{{0}}}",
+    "\u20ee": "\\underledtarrow{{{0}}}",
+    "\u20ef": "\\underrightarrow{{{0}}}",
+    # Over | group
+    "\u23b4": "\\overbracket{{{0}}}",
+    "\u23dc": "\\overparen{{{0}}}",
+    "\u23de": "\\overbrace{{{0}}}",
+    # Under| group
+    "\u23b5": "\\underbracket{{{0}}}",
+    "\u23dd": "\\underparen{{{0}}}",
+    "\u23df": "\\underbrace{{{0}}}",
+}
+
+CHR_BO = {
+    # Big operators,
+    "\u2140": "\\Bbbsum",
+    "\u220f": "\\prod",
+    "\u2210": "\\coprod",
+    "\u2211": "\\sum",
+    "\u222b": "\\int",
+    "\u22c0": "\\bigwedge",
+    "\u22c1": "\\bigvee",
+    "\u22c2": "\\bigcap",
+    "\u22c3": "\\bigcup",
+    "\u2a00": "\\bigodot",
+    "\u2a01": "\\bigoplus",
+    "\u2a02": "\\bigotimes",
+}
+
+T = {
+    "\u2192": "\\rightarrow ",
+    # Greek letters
+    "\U0001d6fc": "\\alpha ",
+    "\U0001d6fd": "\\beta ",
+    "\U0001d6fe": "\\gamma ",
+    "\U0001d6ff": "\\theta ",
+    "\U0001d700": "\\epsilon ",
+    "\U0001d701": "\\zeta ",
+    "\U0001d702": "\\eta ",
+    "\U0001d703": "\\theta ",
+    "\U0001d704": "\\iota ",
+    "\U0001d705": "\\kappa ",
+    "\U0001d706": "\\lambda ",
+    "\U0001d707": "\\m ",
+    "\U0001d708": "\\n ",
+    "\U0001d709": "\\xi ",
+    "\U0001d70a": "\\omicron ",
+    "\U0001d70b": "\\pi ",
+    "\U0001d70c": "\\rho ",
+    "\U0001d70d": "\\varsigma ",
+    "\U0001d70e": "\\sigma ",
+    "\U0001d70f": "\\ta ",
+    "\U0001d710": "\\upsilon ",
+    "\U0001d711": "\\phi ",
+    "\U0001d712": "\\chi ",
+    "\U0001d713": "\\psi ",
+    "\U0001d714": "\\omega ",
+    "\U0001d715": "\\partial ",
+    "\U0001d716": "\\varepsilon ",
+    "\U0001d717": "\\vartheta ",
+    "\U0001d718": "\\varkappa ",
+    "\U0001d719": "\\varphi ",
+    "\U0001d71a": "\\varrho ",
+    "\U0001d71b": "\\varpi ",
+    # Relation symbols
+    "\u2190": "\\leftarrow ",
+    "\u2191": "\\uparrow ",
+    "\u2192": "\\rightarrow ",
+    "\u2193": "\\downright ",
+    "\u2194": "\\leftrightarrow ",
+    "\u2195": "\\updownarrow ",
+    "\u2196": "\\nwarrow ",
+    "\u2197": "\\nearrow ",
+    "\u2198": "\\searrow ",
+    "\u2199": "\\swarrow ",
+    "\u22ee": "\\vdots ",
+    "\u22ef": "\\cdots ",
+    "\u22f0": "\\adots ",
+    "\u22f1": "\\ddots ",
+    "\u2260": "\\ne ",
+    "\u2264": "\\leq ",
+    "\u2265": "\\geq ",
+    "\u2266": "\\leqq ",
+    "\u2267": "\\geqq ",
+    "\u2268": "\\lneqq ",
+    "\u2269": "\\gneqq ",
+    "\u226a": "\\ll ",
+    "\u226b": "\\gg ",
+    "\u2208": "\\in ",
+    "\u2209": "\\notin ",
+    "\u220b": "\\ni ",
+    "\u220c": "\\nni ",
+    # Ordinary symbols
+    "\u221e": "\\infty ",
+    # Binary relations
+    "\u00b1": "\\pm ",
+    "\u2213": "\\mp ",
+    # Italic, Latin, uppercase
+    "\U0001d434": "A",
+    "\U0001d435": "B",
+    "\U0001d436": "C",
+    "\U0001d437": "D",
+    "\U0001d438": "E",
+    "\U0001d439": "F",
+    "\U0001d43a": "G",
+    "\U0001d43b": "H",
+    "\U0001d43c": "I",
+    "\U0001d43d": "J",
+    "\U0001d43e": "K",
+    "\U0001d43f": "L",
+    "\U0001d440": "M",
+    "\U0001d441": "N",
+    "\U0001d442": "O",
+    "\U0001d443": "P",
+    "\U0001d444": "Q",
+    "\U0001d445": "R",
+    "\U0001d446": "S",
+    "\U0001d447": "T",
+    "\U0001d448": "U",
+    "\U0001d449": "V",
+    "\U0001d44a": "W",
+    "\U0001d44b": "X",
+    "\U0001d44c": "Y",
+    "\U0001d44d": "Z",
+    # Italic, Latin, lowercase
+    "\U0001d44e": "a",
+    "\U0001d44f": "b",
+    "\U0001d450": "c",
+    "\U0001d451": "d",
+    "\U0001d452": "e",
+    "\U0001d453": "f",
+    "\U0001d454": "g",
+    "\U0001d456": "i",
+    "\U0001d457": "j",
+    "\U0001d458": "k",
+    "\U0001d459": "l",
+    "\U0001d45a": "m",
+    "\U0001d45b": "n",
+    "\U0001d45c": "o",
+    "\U0001d45d": "p",
+    "\U0001d45e": "q",
+    "\U0001d45f": "r",
+    "\U0001d460": "s",
+    "\U0001d461": "t",
+    "\U0001d462": "u",
+    "\U0001d463": "v",
+    "\U0001d464": "w",
+    "\U0001d465": "x",
+    "\U0001d466": "y",
+    "\U0001d467": "z",
+}
+
+FUNC = {
+    "sin": "\\sin({fe})",
+    "cos": "\\cos({fe})",
+    "tan": "\\tan({fe})",
+    "arcsin": "\\arcsin({fe})",
+    "arccos": "\\arccos({fe})",
+    "arctan": "\\arctan({fe})",
+    "arccot": "\\arccot({fe})",
+    "sinh": "\\sinh({fe})",
+    "cosh": "\\cosh({fe})",
+    "tanh": "\\tanh({fe})",
+    "coth": "\\coth({fe})",
+    "sec": "\\sec({fe})",
+    "csc": "\\csc({fe})",
+}
+
+FUNC_PLACE = "{fe}"
+
+BRK = "\\\\"
+
+CHR_DEFAULT = {
+    "ACC_VAL": "\\hat{{{0}}}",
+}
+
+POS = {
+    "top": "\\overline{{{0}}}",  # not sure
+    "bot": "\\underline{{{0}}}",
+}
+
+POS_DEFAULT = {
+    "BAR_VAL": "\\overline{{{0}}}",
+}
+
+SUB = "_{{{0}}}"
+
+SUP = "^{{{0}}}"
+
+F = {
+    "bar": "\\frac{{{num}}}{{{den}}}",
+    "skw": r"^{{{num}}}/_{{{den}}}",
+    "noBar": "\\genfrac{{}}{{}}{{0pt}}{{}}{{{num}}}{{{den}}}",
+    "lin": "{{{num}}}/{{{den}}}",
+}
+F_DEFAULT = "\\frac{{{num}}}{{{den}}}"
+
+D = "\\left{left}{text}\\right{right}"
+
+D_DEFAULT = {
+    "left": "(",
+    "right": ")",
+    "null": ".",
+}
+
+RAD = "\\sqrt[{deg}]{{{text}}}"
+
+RAD_DEFAULT = "\\sqrt{{{text}}}"
+
+ARR = "\\begin{{array}}{{c}}{text}\\end{{array}}"
+
+LIM_FUNC = {
+    "lim": "\\lim_{{{lim}}}",
+    "max": "\\max_{{{lim}}}",
+    "min": "\\min_{{{lim}}}",
+}
+
+LIM_TO = ("\\rightarrow", "\\to")
+
+LIM_UPP = "\\overset{{{lim}}}{{{text}}}"
+
+M = "\\begin{{matrix}}{text}\\end{{matrix}}"

packages/markitdown/src/markitdown/converter_utils/docx/math/omml.py

@@ -0,0 +1,400 @@
+# -*- coding: utf-8 -*-
+
+"""
+Office Math Markup Language (OMML)
+Adapted from https://github.com/xiilei/dwml/blob/master/dwml/omml.py
+On 25/03/2025
+"""
+
+import xml.etree.ElementTree as ET
+
+from .latex_dict import (
+    CHARS,
+    CHR,
+    CHR_BO,
+    CHR_DEFAULT,
+    POS,
+    POS_DEFAULT,
+    SUB,
+    SUP,
+    F,
+    F_DEFAULT,
+    T,
+    FUNC,
+    D,
+    D_DEFAULT,
+    RAD,
+    RAD_DEFAULT,
+    ARR,
+    LIM_FUNC,
+    LIM_TO,
+    LIM_UPP,
+    M,
+    BRK,
+    BLANK,
+    BACKSLASH,
+    ALN,
+    FUNC_PLACE,
+)
+
+OMML_NS = "{http://schemas.openxmlformats.org/officeDocument/2006/math}"
+
+
+def load(stream):
+    tree = ET.parse(stream)
+    for omath in tree.findall(OMML_NS + "oMath"):
+        yield oMath2Latex(omath)
+
+
+def load_string(string):
+    root = ET.fromstring(string)
+    for omath in root.findall(OMML_NS + "oMath"):
+        yield oMath2Latex(omath)
+
+
+def escape_latex(strs):
+    last = None
+    new_chr = []
+    strs = strs.replace(r"\\", "\\")
+    for c in strs:
+        if (c in CHARS) and (last != BACKSLASH):
+            new_chr.append(BACKSLASH + c)
+        else:
+            new_chr.append(c)
+        last = c
+    return BLANK.join(new_chr)
+
+
+def get_val(key, default=None, store=CHR):
+    if key is not None:
+        return key if not store else store.get(key, key)
+    else:
+        return default
+
+
+class Tag2Method(object):
+    def call_method(self, elm, stag=None):
+        getmethod = self.tag2meth.get
+        if stag is None:
+            stag = elm.tag.replace(OMML_NS, "")
+        method = getmethod(stag)
+        if method:
+            return method(self, elm)
+        else:
+            return None
+
+    def process_children_list(self, elm, include=None):
+        """
+        process children of the elm,return iterable
+        """
+        for _e in list(elm):
+            if OMML_NS not in _e.tag:
+                continue
+            stag = _e.tag.replace(OMML_NS, "")
+            if include and (stag not in include):
+                continue
+            t = self.call_method(_e, stag=stag)
+            if t is None:
+                t = self.process_unknow(_e, stag)
+                if t is None:
+                    continue
+            yield (stag, t, _e)
+
+    def process_children_dict(self, elm, include=None):
+        """
+        process children of the elm,return dict
+        """
+        latex_chars = dict()
+        for stag, t, e in self.process_children_list(elm, include):
+            latex_chars[stag] = t
+        return latex_chars
+
+    def process_children(self, elm, include=None):
+        """
+        process children of the elm,return string
+        """
+        return BLANK.join(
+            (
+                t if not isinstance(t, Tag2Method) else str(t)
+                for stag, t, e in self.process_children_list(elm, include)
+            )
+        )
+
+    def process_unknow(self, elm, stag):
+        return None
+
+
+class Pr(Tag2Method):
+    text = ""
+
+    __val_tags = ("chr", "pos", "begChr", "endChr", "type")
+
+    __innerdict = None  # can't use the __dict__
+
+    """ common properties of element"""
+
+    def __init__(self, elm):
+        self.__innerdict = {}
+        self.text = self.process_children(elm)
+
+    def __str__(self):
+        return self.text
+
+    def __unicode__(self):
+        return self.__str__(self)
+
+    def __getattr__(self, name):
+        return self.__innerdict.get(name, None)
+
+    def do_brk(self, elm):
+        self.__innerdict["brk"] = BRK
+        return BRK
+
+    def do_common(self, elm):
+        stag = elm.tag.replace(OMML_NS, "")
+        if stag in self.__val_tags:
+            t = elm.get("{0}val".format(OMML_NS))
+            self.__innerdict[stag] = t
+        return None
+
+    tag2meth = {
+        "brk": do_brk,
+        "chr": do_common,
+        "pos": do_common,
+        "begChr": do_common,
+        "endChr": do_common,
+        "type": do_common,
+    }
+
+
+class oMath2Latex(Tag2Method):
+    """
+    Convert oMath element of omml to latex
+    """
+
+    _t_dict = T
+
+    __direct_tags = ("box", "sSub", "sSup", "sSubSup", "num", "den", "deg", "e")
+
+    def __init__(self, element):
+        self._latex = self.process_children(element)
+
+    def __str__(self):
+        return self.latex
+
+    def __unicode__(self):
+        return self.__str__(self)
+
+    def process_unknow(self, elm, stag):
+        if stag in self.__direct_tags:
+            return self.process_children(elm)
+        elif stag[-2:] == "Pr":
+            return Pr(elm)
+        else:
+            return None
+
+    @property
+    def latex(self):
+        return self._latex
+
+    def do_acc(self, elm):
+        """
+        the accent function
+        """
+        c_dict = self.process_children_dict(elm)
+        latex_s = get_val(
+            c_dict["accPr"].chr, default=CHR_DEFAULT.get("ACC_VAL"), store=CHR
+        )
+        return latex_s.format(c_dict["e"])
+
+    def do_bar(self, elm):
+        """
+        the bar function
+        """
+        c_dict = self.process_children_dict(elm)
+        pr = c_dict["barPr"]
+        latex_s = get_val(pr.pos, default=POS_DEFAULT.get("BAR_VAL"), store=POS)
+        return pr.text + latex_s.format(c_dict["e"])
+
+    def do_d(self, elm):
+        """
+        the delimiter object
+        """
+        c_dict = self.process_children_dict(elm)
+        pr = c_dict["dPr"]
+        null = D_DEFAULT.get("null")
+        s_val = get_val(pr.begChr, default=D_DEFAULT.get("left"), store=T)
+        e_val = get_val(pr.endChr, default=D_DEFAULT.get("right"), store=T)
+        return pr.text + D.format(
+            left=null if not s_val else escape_latex(s_val),
+            text=c_dict["e"],
+            right=null if not e_val else escape_latex(e_val),
+        )
+
+    def do_spre(self, elm):
+        """
+        the Pre-Sub-Superscript object -- Not support yet
+        """
+        pass
+
+    def do_sub(self, elm):
+        text = self.process_children(elm)
+        return SUB.format(text)
+
+    def do_sup(self, elm):
+        text = self.process_children(elm)
+        return SUP.format(text)
+
+    def do_f(self, elm):
+        """
+        the fraction object
+        """
+        c_dict = self.process_children_dict(elm)
+        pr = c_dict["fPr"]
+        latex_s = get_val(pr.type, default=F_DEFAULT, store=F)
+        return pr.text + latex_s.format(num=c_dict.get("num"), den=c_dict.get("den"))
+
+    def do_func(self, elm):
+        """
+        the Function-Apply object (Examples:sin cos)
+        """
+        c_dict = self.process_children_dict(elm)
+        func_name = c_dict.get("fName")
+        return func_name.replace(FUNC_PLACE, c_dict.get("e"))
+
+    def do_fname(self, elm):
+        """
+        the func name
+        """
+        latex_chars = []
+        for stag, t, e in self.process_children_list(elm):
+            if stag == "r":
+                if FUNC.get(t):
+                    latex_chars.append(FUNC[t])
+                else:
+                    raise NotImplemented("Not support func %s" % t)
+            else:
+                latex_chars.append(t)
+        t = BLANK.join(latex_chars)
+        return t if FUNC_PLACE in t else t + FUNC_PLACE  # do_func will replace this
+
+    def do_groupchr(self, elm):
+        """
+        the Group-Character object
+        """
+        c_dict = self.process_children_dict(elm)
+        pr = c_dict["groupChrPr"]
+        latex_s = get_val(pr.chr)
+        return pr.text + latex_s.format(c_dict["e"])
+
+    def do_rad(self, elm):
+        """
+        the radical object
+        """
+        c_dict = self.process_children_dict(elm)
+        text = c_dict.get("e")
+        deg_text = c_dict.get("deg")
+        if deg_text:
+            return RAD.format(deg=deg_text, text=text)
+        else:
+            return RAD_DEFAULT.format(text=text)
+
+    def do_eqarr(self, elm):
+        """
+        the Array object
+        """
+        return ARR.format(
+            text=BRK.join(
+                [t for stag, t, e in self.process_children_list(elm, include=("e",))]
+            )
+        )
+
+    def do_limlow(self, elm):
+        """
+        the Lower-Limit object
+        """
+        t_dict = self.process_children_dict(elm, include=("e", "lim"))
+        latex_s = LIM_FUNC.get(t_dict["e"])
+        if not latex_s:
+            raise NotImplemented("Not support lim %s" % t_dict["e"])
+        else:
+            return latex_s.format(lim=t_dict.get("lim"))
+
+    def do_limupp(self, elm):
+        """
+        the Upper-Limit object
+        """
+        t_dict = self.process_children_dict(elm, include=("e", "lim"))
+        return LIM_UPP.format(lim=t_dict.get("lim"), text=t_dict.get("e"))
+
+    def do_lim(self, elm):
+        """
+        the lower limit of the limLow object and the upper limit of the limUpp function
+        """
+        return self.process_children(elm).replace(LIM_TO[0], LIM_TO[1])
+
+    def do_m(self, elm):
+        """
+        the Matrix object
+        """
+        rows = []
+        for stag, t, e in self.process_children_list(elm):
+            if stag == "mPr":
+                pass
+            elif stag == "mr":
+                rows.append(t)
+        return M.format(text=BRK.join(rows))
+
+    def do_mr(self, elm):
+        """
+        a single row of the matrix m
+        """
+        return ALN.join(
+            [t for stag, t, e in self.process_children_list(elm, include=("e",))]
+        )
+
+    def do_nary(self, elm):
+        """
+        the n-ary object
+        """
+        res = []
+        bo = ""
+        for stag, t, e in self.process_children_list(elm):
+            if stag == "naryPr":
+                bo = get_val(t.chr, store=CHR_BO)
+            else:
+                res.append(t)
+        return bo + BLANK.join(res)
+
+    def do_r(self, elm):
+        """
+        Get text from 'r' element,And try convert them to latex symbols
+        @todo text style support , (sty)
+        @todo \text (latex pure text support)
+        """
+        _str = []
+        for s in elm.findtext("./{0}t".format(OMML_NS)):
+            # s = s if isinstance(s,unicode) else unicode(s,'utf-8')
+            _str.append(self._t_dict.get(s, s))
+        return escape_latex(BLANK.join(_str))
+
+    tag2meth = {
+        "acc": do_acc,
+        "r": do_r,
+        "bar": do_bar,
+        "sub": do_sub,
+        "sup": do_sup,
+        "f": do_f,
+        "func": do_func,
+        "fName": do_fname,
+        "groupChr": do_groupchr,
+        "d": do_d,
+        "rad": do_rad,
+        "eqArr": do_eqarr,
+        "limLow": do_limlow,
+        "limUpp": do_limupp,
+        "lim": do_lim,
+        "m": do_m,
+        "mr": do_mr,
+        "nary": do_nary,
+    }

packages/markitdown/src/markitdown/converter_utils/docx/pre_process.py

@@ -0,0 +1,156 @@
+import zipfile
+from io import BytesIO
+from typing import BinaryIO
+from xml.etree import ElementTree as ET
+
+from bs4 import BeautifulSoup, Tag
+
+from .math.omml import OMML_NS, oMath2Latex
+
+MATH_ROOT_TEMPLATE = "".join(
+    (
+        "<w:document ",
+        'xmlns:wpc="http://schemas.microsoft.com/office/word/2010/wordprocessingCanvas" ',
+        'xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" ',
+        'xmlns:o="urn:schemas-microsoft-com:office:office" ',
+        'xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships" ',
+        'xmlns:m="http://schemas.openxmlformats.org/officeDocument/2006/math" ',
+        'xmlns:v="urn:schemas-microsoft-com:vml" ',
+        'xmlns:wp14="http://schemas.microsoft.com/office/word/2010/wordprocessingDrawing" ',
+        'xmlns:wp="http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawing" ',
+        'xmlns:w10="urn:schemas-microsoft-com:office:word" ',
+        'xmlns:w="http://schemas.openxmlformats.org/wordprocessingml/2006/main" ',
+        'xmlns:w14="http://schemas.microsoft.com/office/word/2010/wordml" ',
+        'xmlns:wpg="http://schemas.microsoft.com/office/word/2010/wordprocessingGroup" ',
+        'xmlns:wpi="http://schemas.microsoft.com/office/word/2010/wordprocessingInk" ',
+        'xmlns:wne="http://schemas.microsoft.com/office/word/2006/wordml" ',
+        'xmlns:wps="http://schemas.microsoft.com/office/word/2010/wordprocessingShape" mc:Ignorable="w14 wp14">',
+        "{0}</w:document>",
+    )
+)
+
+
+def _convert_omath_to_latex(tag: Tag) -> str:
+    """
+    Converts an OMML (Office Math Markup Language) tag to LaTeX format.
+
+    Args:
+        tag (Tag): A BeautifulSoup Tag object representing the OMML element.
+
+    Returns:
+        str: The LaTeX representation of the OMML element.
+    """
+    # Format the tag into a complete XML document string
+    math_root = ET.fromstring(MATH_ROOT_TEMPLATE.format(str(tag)))
+    # Find the 'oMath' element within the XML document
+    math_element = math_root.find(OMML_NS + "oMath")
+    # Convert the 'oMath' element to LaTeX using the oMath2Latex function
+    latex = oMath2Latex(math_element).latex
+    return latex
+
+
+def _get_omath_tag_replacement(tag: Tag, block: bool = False) -> Tag:
+    """
+    Creates a replacement tag for an OMML (Office Math Markup Language) element.
+
+    Args:
+        tag (Tag): A BeautifulSoup Tag object representing the "oMath" element.
+        block (bool, optional): If True, the LaTeX will be wrapped in double dollar signs for block mode. Defaults to False.
+
+    Returns:
+        Tag: A BeautifulSoup Tag object representing the replacement element.
+    """
+    t_tag = Tag(name="w:t")
+    t_tag.string = (
+        f"$${_convert_omath_to_latex(tag)}$$"
+        if block
+        else f"${_convert_omath_to_latex(tag)}$"
+    )
+    r_tag = Tag(name="w:r")
+    r_tag.append(t_tag)
+    return r_tag
+
+
+def _replace_equations(tag: Tag):
+    """
+    Replaces OMML (Office Math Markup Language) elements with their LaTeX equivalents.
+
+    Args:
+        tag (Tag): A BeautifulSoup Tag object representing the OMML element. Could be either "oMathPara" or "oMath".
+
+    Raises:
+        ValueError: If the tag is not supported.
+    """
+    if tag.name == "oMathPara":
+        # Create a new paragraph tag
+        p_tag = Tag(name="w:p")
+        # Replace each 'oMath' child tag with its LaTeX equivalent as block equations
+        for child_tag in tag.find_all("oMath"):
+            p_tag.append(_get_omath_tag_replacement(child_tag, block=True))
+        # Replace the original 'oMathPara' tag with the new paragraph tag
+        tag.replace_with(p_tag)
+    elif tag.name == "oMath":
+        # Replace the 'oMath' tag with its LaTeX equivalent as inline equation
+        tag.replace_with(_get_omath_tag_replacement(tag, block=False))
+    else:
+        raise ValueError(f"Not supported tag: {tag.name}")
+
+
+def _pre_process_math(content: bytes) -> bytes:
+    """
+    Pre-processes the math content in a DOCX -> XML file by converting OMML (Office Math Markup Language) elements to LaTeX.
+    This preprocessed content can be directly replaced in the DOCX file -> XMLs.
+
+    Args:
+        content (bytes): The XML content of the DOCX file as bytes.
+
+    Returns:
+        bytes: The processed content with OMML elements replaced by their LaTeX equivalents, encoded as bytes.
+    """
+    soup = BeautifulSoup(content.decode(), features="xml")
+    for tag in soup.find_all("oMathPara"):
+        _replace_equations(tag)
+    for tag in soup.find_all("oMath"):
+        _replace_equations(tag)
+    return str(soup).encode()
+
+
+def pre_process_docx(input_docx: BinaryIO) -> BinaryIO:
+    """
+    Pre-processes a DOCX file with provided steps.
+
+    The process works by unzipping the DOCX file in memory, transforming specific XML files
+    (such as converting OMML elements to LaTeX), and then zipping everything back into a
+    DOCX file without writing to disk.
+
+    Args:
+        input_docx (BinaryIO): A binary input stream representing the DOCX file.
+
+    Returns:
+        BinaryIO: A binary output stream representing the processed DOCX file.
+    """
+    output_docx = BytesIO()
+    # The files that need to be pre-processed from .docx
+    pre_process_enable_files = [
+        "word/document.xml",
+        "word/footnotes.xml",
+        "word/endnotes.xml",
+    ]
+    with zipfile.ZipFile(input_docx, mode="r") as zip_input:
+        files = {name: zip_input.read(name) for name in zip_input.namelist()}
+        with zipfile.ZipFile(output_docx, mode="w") as zip_output:
+            zip_output.comment = zip_input.comment
+            for name, content in files.items():
+                if name in pre_process_enable_files:
+                    try:
+                        # Pre-process the content
+                        updated_content = _pre_process_math(content)
+                        # In the future, if there are more pre-processing steps, they can be added here
+                        zip_output.writestr(name, updated_content)
+                    except:
+                        # If there is an error in processing the content, write the original content
+                        zip_output.writestr(name, content)
+                else:
+                    zip_output.writestr(name, content)
+    output_docx.seek(0)
+    return output_docx

packages/markitdown/src/markitdown/converters/_docx_converter.py

@@ -3,6 +3,7 @@ import sys
 from typing import BinaryIO, Any
 
 from ._html_converter import HtmlConverter
+from ..converter_utils.docx.pre_process import pre_process_docx
 from .._base_converter import DocumentConverter, DocumentConverterResult
 from .._stream_info import StreamInfo
 from .._exceptions import MissingDependencyException, MISSING_DEPENDENCY_MESSAGE
@@ -72,6 +73,8 @@ class DocxConverter(HtmlConverter):
             )
 
         style_map = kwargs.get("style_map", None)
+        pre_process_stream = pre_process_docx(file_stream)
         return self._html_converter.convert_string(
-            mammoth.convert_to_html(file_stream, style_map=style_map).value, **kwargs
+            mammoth.convert_to_html(pre_process_stream, style_map=style_map).value,
+            **kwargs,
         )

packages/markitdown/tests/test_module_misc.py

@@ -1,6 +1,7 @@
 #!/usr/bin/env python3 -m pytest
 import io
 import os
+import re
 import shutil
 import openai
 import pytest
@@ -262,6 +263,19 @@ def test_docx_comments() -> None:
     validate_strings(result, DOCX_COMMENT_TEST_STRINGS)
 
 
+def test_docx_equations() -> None:
+    markitdown = MarkItDown()
+    docx_file = os.path.join(TEST_FILES_DIR, "equations.docx")
+    result = markitdown.convert(docx_file)
+
+    # Check for inline equation m=1 (wrapped with single $) is present
+    assert "$m=1$" in result.text_content, "Inline equation $m=1$ not found"
+
+    # Find block equations wrapped with double $$ and check if they are present
+    block_equations = re.findall(r"\$\$(.+?)\$\$", result.text_content)
+    assert block_equations, "No block equations found in the document."
+
+
 def test_input_as_strings() -> None:
     markitdown = MarkItDown()