2 - Patent Expiration Dates.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Patent Expiration Dates\n",
    "\n",
    "Let's see how we can estimate utility patent expiration dates using patent_client. The relevant law describes the expiration date as:\n",
    "\n",
    "> **35 U.S.C. 154(a)(2)-(3)** \n",
    "\n",
    ">*(2)Term.—*\n",
    "Subject to the payment of fees under this title, such grant shall be for a term beginning on the date on which the patent issues and ending 20 years from the date on which the application for the patent was filed in the United States or, if the application contains a specific reference to an earlier filed application or applications under section 120, 121, 365(c), or 386(c), from the date on which the earliest such application was filed.\n",
    "\n",
    ">*(3)Priority.—*\n",
    "Priority under section 119, 365(a), 365(b), 386(a), or 386(b) shall not be taken into account in determining the term of a patent.\n",
    "\n",
    "To unpack that a bit, the default term is 20 years from the earliest of:\n",
    "\n",
    "- the patent's filing date\n",
    "- the filing date of any continuation or continuation-in-part (section 120), divisional (section 121), or\n",
    "- a US Application claiming priority to a PCT patent or Hague Convention design patent application (365(b) / 386(b))\n",
    "\n",
    "From there, there can be extensions and limits, but we'll address that after we can figure out the default term.\n"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "We'll use Tesla's patents as an example here. First, let's fetch their portfolio, and then filter out cases that dont have a patent number, and that aren't design patents (which have a different rule):"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 17,
   "metadata": {},
   "outputs": [],
   "source": [
    "import pandas as pd\n",
    "from patent_client import USApplication, Assignment\n",
    "\n",
    "company_name = 'Tesla Motors'\n",
    "applicant_apps = USApplication.objects.filter(first_named_applicant=company_name)\n",
    "patents = [a for a in applicant_apps if hasattr(a, 'patent_number') and a.app_type == 'Utility']# Selects only cases that have a patent number\n"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Default Patent Term\n",
    "\n",
    "To figure out 20 years from their original filing date is pretty easy, so let's do that. We'll pull in another Python library called dateutil that has an easy-to-use class called \"relativedelta\" that's great for these kinds of calculations:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 18,
   "metadata": {},
   "outputs": [
    {
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       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>application_number</th>\n",
       "      <th>filing_date</th>\n",
       "      <th>20_years_from_filing</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>8807637</th>\n",
       "      <td>13621943</td>\n",
       "      <td>2012-09-18</td>\n",
       "      <td>2032-09-18</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9209631</th>\n",
       "      <td>13624900</td>\n",
       "      <td>2012-09-22</td>\n",
       "      <td>2032-09-22</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9103143</th>\n",
       "      <td>13626864</td>\n",
       "      <td>2012-09-25</td>\n",
       "      <td>2032-09-25</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9151089</th>\n",
       "      <td>13627903</td>\n",
       "      <td>2012-09-26</td>\n",
       "      <td>2032-09-26</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>8807807</th>\n",
       "      <td>13628034</td>\n",
       "      <td>2012-09-26</td>\n",
       "      <td>2032-09-26</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "        application_number filing_date 20_years_from_filing\n",
       "8807637           13621943  2012-09-18           2032-09-18\n",
       "9209631           13624900  2012-09-22           2032-09-22\n",
       "9103143           13626864  2012-09-25           2032-09-25\n",
       "9151089           13627903  2012-09-26           2032-09-26\n",
       "8807807           13628034  2012-09-26           2032-09-26"
      ]
     },
     "execution_count": 18,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "from dateutil.relativedelta import relativedelta\n",
    "\n",
    "default_expiry = pd.DataFrame(data={\n",
    "    'application_number': [a.appl_id for a in patents],\n",
    "    'filing_date': [a.app_filing_date for a in patents],\n",
    "    '20_years_from_filing': [a.app_filing_date + relativedelta(years=20) for a in patents]\n",
    "}, index=[a.patent_number for a in patents])\n",
    "\n",
    "default_expiry.head()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "But that isn't quite what we want. We want to look at all the parent cases for each application, and see if there are parent cases that fall into one of the categories mentioned above. We know that we don't need to worry about the foreign priority problems, because USApplications stores foreign priority data (which is irrelevant) in the USApplication.foreign_priority attribute. But what is in \"parents\"?\n",
    "\n",
    "Let's first take a peek at what all the relationship data looks like for all the cases by collecting all the parents, and then looking at all non-duplicate relationship types:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 19,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "is a Continuation in part of\n",
      "is National Stage Entry of\n",
      "Claims Priority from Provisional Application\n",
      "is a Continuation of\n",
      "is a Division of\n"
     ]
    }
   ],
   "source": [
    "parents = list()\n",
    "for p in patents:\n",
    "    parents += p.parents\n",
    "\n",
    "relationship_types = list(set(p.relationship for p in parents))\n",
    "\n",
    "for t in relationship_types:\n",
    "    print(t)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "From this, we see the only things we want to exclude are Provisional Applications (filed under section 119), and reissue applications (filed under section 251). The rest fall squarely into the categories listed above. So, let's write a simple function that takes an application and figures out the earliest priority date that isn't a Provisional Application or a Reissue, and then apply it to create a new DataFrame."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 20,
   "metadata": {},
   "outputs": [
    {
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       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>application_number</th>\n",
       "      <th>filing_date</th>\n",
       "      <th>number_of_parents</th>\n",
       "      <th>earliest_parent_case</th>\n",
       "      <th>earliest_parent_relationship</th>\n",
       "      <th>earliest_parent_filing_date</th>\n",
       "      <th>20_years_from_filing</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>8807637</th>\n",
       "      <td>13621943</td>\n",
       "      <td>2012-09-18</td>\n",
       "      <td>1</td>\n",
       "      <td>13621943</td>\n",
       "      <td>Self</td>\n",
       "      <td>2012-09-18</td>\n",
       "      <td>2032-09-18</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9209631</th>\n",
       "      <td>13624900</td>\n",
       "      <td>2012-09-22</td>\n",
       "      <td>2</td>\n",
       "      <td>12887557</td>\n",
       "      <td>is a Division of</td>\n",
       "      <td>2010-09-22</td>\n",
       "      <td>2030-09-22</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9103143</th>\n",
       "      <td>13626864</td>\n",
       "      <td>2012-09-25</td>\n",
       "      <td>4</td>\n",
       "      <td>13626864</td>\n",
       "      <td>Self</td>\n",
       "      <td>2012-09-25</td>\n",
       "      <td>2032-09-25</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9151089</th>\n",
       "      <td>13627903</td>\n",
       "      <td>2012-09-26</td>\n",
       "      <td>4</td>\n",
       "      <td>13627903</td>\n",
       "      <td>Self</td>\n",
       "      <td>2012-09-26</td>\n",
       "      <td>2032-09-26</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>8807807</th>\n",
       "      <td>13628034</td>\n",
       "      <td>2012-09-26</td>\n",
       "      <td>4</td>\n",
       "      <td>13628034</td>\n",
       "      <td>Self</td>\n",
       "      <td>2012-09-26</td>\n",
       "      <td>2032-09-26</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "        application_number filing_date  number_of_parents  \\\n",
       "8807637           13621943  2012-09-18                  1   \n",
       "9209631           13624900  2012-09-22                  2   \n",
       "9103143           13626864  2012-09-25                  4   \n",
       "9151089           13627903  2012-09-26                  4   \n",
       "8807807           13628034  2012-09-26                  4   \n",
       "\n",
       "        earliest_parent_case earliest_parent_relationship  \\\n",
       "8807637             13621943                         Self   \n",
       "9209631             12887557             is a Division of   \n",
       "9103143             13626864                         Self   \n",
       "9151089             13627903                         Self   \n",
       "8807807             13628034                         Self   \n",
       "\n",
       "        earliest_parent_filing_date 20_years_from_filing  \n",
       "8807637                  2012-09-18           2032-09-18  \n",
       "9209631                  2010-09-22           2030-09-22  \n",
       "9103143                  2012-09-25           2032-09-25  \n",
       "9151089                  2012-09-26           2032-09-26  \n",
       "8807807                  2012-09-26           2032-09-26  "
      ]
     },
     "execution_count": 20,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "\n",
    "class Relationship():\n",
    "    pass\n",
    "\n",
    "def earliest_term_parent(app):\n",
    "    parents = app.parents\n",
    "    term_parents = [p for p in parents \n",
    "                    if p.relationship not in [\n",
    "                        'Claims Priority from Provisional Application',\n",
    "                        'is a Reissue of'\n",
    "                    ]]\n",
    "    if not term_parents:\n",
    "        # Create a dummy relationship if there are no matching relationships\n",
    "        earliest_parent = Relationship()\n",
    "        earliest_parent.filing_date = app.app_filing_date\n",
    "        earliest_parent.relationship = 'Self'\n",
    "        earliest_parent.appl_id = app.appl_id\n",
    "        return earliest_parent\n",
    "    earliest_parent = sorted(term_parents, key=lambda x: x.filing_date)[0]\n",
    "    return earliest_parent\n",
    "\n",
    "earliest_parents = [earliest_term_parent(p) for p in patents]\n",
    "\n",
    "default_expiry = pd.DataFrame(data={\n",
    "    'application_number': [a.appl_id for a in patents],\n",
    "    'filing_date': [a.app_filing_date for a in patents],\n",
    "    'number_of_parents': [len(p.parents) for p in patents],\n",
    "    'earliest_parent_case': [p.appl_id for p in earliest_parents],\n",
    "    'earliest_parent_relationship': [p.relationship for p in earliest_parents],\n",
    "    'earliest_parent_filing_date': [p.filing_date for p in earliest_parents],\n",
    "    '20_years_from_filing': [p.filing_date + relativedelta(years=20) for p in earliest_parents],\n",
    "}, index=[a.patent_number for a in patents])\n",
    "\n",
    "default_expiry.head()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "As a sanity check, let's grab the case with the largest number of parents, and make sure the right one was picked:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 21,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "application_number                                  15384723\n",
      "filing_date                                       2016-12-20\n",
      "number_of_parents                                          6\n",
      "earliest_parent_case                                12322218\n",
      "earliest_parent_relationship    is a Continuation in part of\n",
      "earliest_parent_filing_date                       2009-01-29\n",
      "20_years_from_filing                              2029-01-29\n",
      "Name: 10131248, dtype: object\n"
     ]
    },
    {
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       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>appl_id</th>\n",
       "      <th>filing_date</th>\n",
       "      <th>patent_number</th>\n",
       "      <th>relationship</th>\n",
       "      <th>status</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>4</th>\n",
       "      <td>12322218</td>\n",
       "      <td>2009-01-29</td>\n",
       "      <td>None</td>\n",
       "      <td>is a Continuation in part of</td>\n",
       "      <td>None</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5</th>\n",
       "      <td>12380427</td>\n",
       "      <td>2009-02-26</td>\n",
       "      <td>7739005</td>\n",
       "      <td>is a Continuation in part of</td>\n",
       "      <td>None</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>12782413</td>\n",
       "      <td>2010-05-18</td>\n",
       "      <td>8453770</td>\n",
       "      <td>is a Division of</td>\n",
       "      <td>None</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>13866214</td>\n",
       "      <td>2013-04-19</td>\n",
       "      <td>8761985</td>\n",
       "      <td>is a Continuation of</td>\n",
       "      <td>None</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>14281679</td>\n",
       "      <td>2014-05-19</td>\n",
       "      <td>9162586</td>\n",
       "      <td>is a Continuation of</td>\n",
       "      <td>None</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>14862609</td>\n",
       "      <td>2015-09-23</td>\n",
       "      <td>9527406</td>\n",
       "      <td>is a Continuation of</td>\n",
       "      <td>None</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "    appl_id filing_date patent_number                  relationship status\n",
       "4  12322218  2009-01-29          None  is a Continuation in part of   None\n",
       "5  12380427  2009-02-26       7739005  is a Continuation in part of   None\n",
       "3  12782413  2010-05-18       8453770              is a Division of   None\n",
       "2  13866214  2013-04-19       8761985          is a Continuation of   None\n",
       "1  14281679  2014-05-19       9162586          is a Continuation of   None\n",
       "0  14862609  2015-09-23       9527406          is a Continuation of   None"
      ]
     },
     "execution_count": 21,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "row = default_expiry.sort_values('number_of_parents', ascending=False).iloc[0]\n",
    "print(row)\n",
    "app_id = row['application_number']\n",
    "app = next(p for p in patents if p.appl_id == app_id)\n",
    "pd.DataFrame.from_records(r.as_dict() for r in app.parents).sort_values('filing_date')"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Everything checks out! The oldest case that matches our critera is the one that our function picked!"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Patent Term Extension\n",
    "\n",
    "Occasionally, the patent office moves slowly in granting patents. To prevent patentees from losing out on patent term, the USPTO can add back days lost due to USPTO delay. The fine-grained details aren't important here, because under USPTO regs, the term extension is set when the patent issues, and cannot be changed. If the USPTO made a mistake in calculating the term extension, a petition has to be filed immediately. [MPEP Sec. 2733](https://www.uspto.gov/web/offices/pac/mpep/s2733.html).\n",
    "\n",
    "For our purposes, the number we need is available under the pta_pte_summary composite object. Let's take a look at an example:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 22,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "{'a_delay': 518,\n",
      " 'applicant_delay': 0,\n",
      " 'b_delay': 77,\n",
      " 'c_delay': 0,\n",
      " 'overlap_delay': 0,\n",
      " 'pto_adjustments': 0,\n",
      " 'pto_delay': 595,\n",
      " 'total_days': 595,\n",
      " 'type': 'PTA'}\n"
     ]
    }
   ],
   "source": [
    "from pprint import pprint\n",
    "pprint(next(p.pta_pte_summary.as_dict() for p in patents if p.pta_pte_summary.total_days > 0))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "All we're interested in is \"total days\" which is a number of days to be added to the patent term. Let's grab that data, and add it to our dataframe:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 23,
   "metadata": {},
   "outputs": [
    {
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       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>application_number</th>\n",
       "      <th>filing_date</th>\n",
       "      <th>number_of_parents</th>\n",
       "      <th>earliest_parent_case</th>\n",
       "      <th>earliest_parent_relationship</th>\n",
       "      <th>earliest_parent_filing_date</th>\n",
       "      <th>20_years_from_filing</th>\n",
       "      <th>PTA or PTE</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>8807637</th>\n",
       "      <td>13621943</td>\n",
       "      <td>2012-09-18</td>\n",
       "      <td>1</td>\n",
       "      <td>13621943</td>\n",
       "      <td>Self</td>\n",
       "      <td>2012-09-18</td>\n",
       "      <td>2032-09-18</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9209631</th>\n",
       "      <td>13624900</td>\n",
       "      <td>2012-09-22</td>\n",
       "      <td>2</td>\n",
       "      <td>12887557</td>\n",
       "      <td>is a Division of</td>\n",
       "      <td>2010-09-22</td>\n",
       "      <td>2030-09-22</td>\n",
       "      <td>595</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9103143</th>\n",
       "      <td>13626864</td>\n",
       "      <td>2012-09-25</td>\n",
       "      <td>4</td>\n",
       "      <td>13626864</td>\n",
       "      <td>Self</td>\n",
       "      <td>2012-09-25</td>\n",
       "      <td>2032-09-25</td>\n",
       "      <td>413</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9151089</th>\n",
       "      <td>13627903</td>\n",
       "      <td>2012-09-26</td>\n",
       "      <td>4</td>\n",
       "      <td>13627903</td>\n",
       "      <td>Self</td>\n",
       "      <td>2012-09-26</td>\n",
       "      <td>2032-09-26</td>\n",
       "      <td>372</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>8807807</th>\n",
       "      <td>13628034</td>\n",
       "      <td>2012-09-26</td>\n",
       "      <td>4</td>\n",
       "      <td>13628034</td>\n",
       "      <td>Self</td>\n",
       "      <td>2012-09-26</td>\n",
       "      <td>2032-09-26</td>\n",
       "      <td>199</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "        application_number filing_date  number_of_parents  \\\n",
       "8807637           13621943  2012-09-18                  1   \n",
       "9209631           13624900  2012-09-22                  2   \n",
       "9103143           13626864  2012-09-25                  4   \n",
       "9151089           13627903  2012-09-26                  4   \n",
       "8807807           13628034  2012-09-26                  4   \n",
       "\n",
       "        earliest_parent_case earliest_parent_relationship  \\\n",
       "8807637             13621943                         Self   \n",
       "9209631             12887557             is a Division of   \n",
       "9103143             13626864                         Self   \n",
       "9151089             13627903                         Self   \n",
       "8807807             13628034                         Self   \n",
       "\n",
       "        earliest_parent_filing_date 20_years_from_filing  PTA or PTE  \n",
       "8807637                  2012-09-18           2032-09-18           0  \n",
       "9209631                  2010-09-22           2030-09-22         595  \n",
       "9103143                  2012-09-25           2032-09-25         413  \n",
       "9151089                  2012-09-26           2032-09-26         372  \n",
       "8807807                  2012-09-26           2032-09-26         199  "
      ]
     },
     "execution_count": 23,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "pta_df = pd.DataFrame(\n",
    "    {\n",
    "        'PTA or PTE': [p.pta_pte_summary.total_days for p in patents]\n",
    "    }, index=[p.patent_number for p in patents])\n",
    "\n",
    "expiry_df = default_expiry.join(pta_df)\n",
    "expiry_df.head()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Lastly, let's include that in our expiration date calculation"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 24,
   "metadata": {},
   "outputs": [
    {
     "data": {
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       "    }\n",
       "\n",
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       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>application_number</th>\n",
       "      <th>filing_date</th>\n",
       "      <th>number_of_parents</th>\n",
       "      <th>earliest_parent_case</th>\n",
       "      <th>earliest_parent_relationship</th>\n",
       "      <th>earliest_parent_filing_date</th>\n",
       "      <th>20_years_from_filing</th>\n",
       "      <th>PTA or PTE</th>\n",
       "      <th>extended_expiration_date</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>8807637</th>\n",
       "      <td>13621943</td>\n",
       "      <td>2012-09-18</td>\n",
       "      <td>1</td>\n",
       "      <td>13621943</td>\n",
       "      <td>Self</td>\n",
       "      <td>2012-09-18</td>\n",
       "      <td>2032-09-18</td>\n",
       "      <td>0</td>\n",
       "      <td>2032-09-18</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9209631</th>\n",
       "      <td>13624900</td>\n",
       "      <td>2012-09-22</td>\n",
       "      <td>2</td>\n",
       "      <td>12887557</td>\n",
       "      <td>is a Division of</td>\n",
       "      <td>2010-09-22</td>\n",
       "      <td>2030-09-22</td>\n",
       "      <td>595</td>\n",
       "      <td>2032-05-09</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9103143</th>\n",
       "      <td>13626864</td>\n",
       "      <td>2012-09-25</td>\n",
       "      <td>4</td>\n",
       "      <td>13626864</td>\n",
       "      <td>Self</td>\n",
       "      <td>2012-09-25</td>\n",
       "      <td>2032-09-25</td>\n",
       "      <td>413</td>\n",
       "      <td>2033-11-12</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9151089</th>\n",
       "      <td>13627903</td>\n",
       "      <td>2012-09-26</td>\n",
       "      <td>4</td>\n",
       "      <td>13627903</td>\n",
       "      <td>Self</td>\n",
       "      <td>2012-09-26</td>\n",
       "      <td>2032-09-26</td>\n",
       "      <td>372</td>\n",
       "      <td>2033-10-03</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>8807807</th>\n",
       "      <td>13628034</td>\n",
       "      <td>2012-09-26</td>\n",
       "      <td>4</td>\n",
       "      <td>13628034</td>\n",
       "      <td>Self</td>\n",
       "      <td>2012-09-26</td>\n",
       "      <td>2032-09-26</td>\n",
       "      <td>199</td>\n",
       "      <td>2033-04-13</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "        application_number filing_date  number_of_parents  \\\n",
       "8807637           13621943  2012-09-18                  1   \n",
       "9209631           13624900  2012-09-22                  2   \n",
       "9103143           13626864  2012-09-25                  4   \n",
       "9151089           13627903  2012-09-26                  4   \n",
       "8807807           13628034  2012-09-26                  4   \n",
       "\n",
       "        earliest_parent_case earliest_parent_relationship  \\\n",
       "8807637             13621943                         Self   \n",
       "9209631             12887557             is a Division of   \n",
       "9103143             13626864                         Self   \n",
       "9151089             13627903                         Self   \n",
       "8807807             13628034                         Self   \n",
       "\n",
       "        earliest_parent_filing_date 20_years_from_filing  PTA or PTE  \\\n",
       "8807637                  2012-09-18           2032-09-18           0   \n",
       "9209631                  2010-09-22           2030-09-22         595   \n",
       "9103143                  2012-09-25           2032-09-25         413   \n",
       "9151089                  2012-09-26           2032-09-26         372   \n",
       "8807807                  2012-09-26           2032-09-26         199   \n",
       "\n",
       "        extended_expiration_date  \n",
       "8807637               2032-09-18  \n",
       "9209631               2032-05-09  \n",
       "9103143               2033-11-12  \n",
       "9151089               2033-10-03  \n",
       "8807807               2033-04-13  "
      ]
     },
     "execution_count": 24,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "expiry_df['extended_expiration_date'] = expiry_df.apply(lambda x: x['20_years_from_filing'] + relativedelta(days=x['PTA or PTE']), axis=1)\n",
    "expiry_df.head()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Terminal Disclaimers\n",
    "\n",
    "The last step in calculating patent expiration dates is to see if the patent is subject to a terminal disclaimer. Unfortunately, the USApplication object can't tell you what cases the application is terminally disclaimed over, but it can tell you whether a terminal disclaimer has been filed. That information is in the Transaction History. The \"Terminal Disclaimer Filed\" transaction code is \"DIST\" (See [Transaction Codes](https://www.uspto.gov/sites/default/files/documents/Appendix%20B.pdf))\n",
    "\n",
    "Therefore, what we can do is add a flag to our expiration date calculation to tell us whether we need to go check the file history to determine if there is a terminal disclaimer. To make it useful, we'ill include the date the terminal disclaimer was filed (so we can find it easily) or if none, we'll leave it blank:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 31,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
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       "      <th>terminal_disclaimer_filed</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>10011157</th>\n",
       "      <td>14803747</td>\n",
       "      <td>2015-07-20</td>\n",
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       "      <td>14803747</td>\n",
       "      <td>Self</td>\n",
       "      <td>2015-07-20</td>\n",
       "      <td>2035-07-20</td>\n",
       "      <td>379</td>\n",
       "      <td>2036-08-02</td>\n",
       "      <td>None</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>10018681</th>\n",
       "      <td>15002710</td>\n",
       "      <td>2016-01-21</td>\n",
       "      <td>1</td>\n",
       "      <td>15002710</td>\n",
       "      <td>Self</td>\n",
       "      <td>2016-01-21</td>\n",
       "      <td>2036-01-21</td>\n",
       "      <td>370</td>\n",
       "      <td>2037-01-25</td>\n",
       "      <td>None</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>10019066</th>\n",
       "      <td>13765363</td>\n",
       "      <td>2013-02-12</td>\n",
       "      <td>2</td>\n",
       "      <td>13764942</td>\n",
       "      <td>is a Continuation of</td>\n",
       "      <td>2013-02-12</td>\n",
       "      <td>2033-02-12</td>\n",
       "      <td>544</td>\n",
       "      <td>2034-08-10</td>\n",
       "      <td>2018-03-05</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>10023038</th>\n",
       "      <td>14703646</td>\n",
       "      <td>2015-05-04</td>\n",
       "      <td>3</td>\n",
       "      <td>13308300</td>\n",
       "      <td>is a Continuation of</td>\n",
       "      <td>2011-11-30</td>\n",
       "      <td>2031-11-30</td>\n",
       "      <td>0</td>\n",
       "      <td>2031-11-30</td>\n",
       "      <td>None</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>10046422</th>\n",
       "      <td>15099883</td>\n",
       "      <td>2016-04-15</td>\n",
       "      <td>1</td>\n",
       "      <td>13886672</td>\n",
       "      <td>is a Division of</td>\n",
       "      <td>2013-05-03</td>\n",
       "      <td>2033-05-03</td>\n",
       "      <td>320</td>\n",
       "      <td>2034-03-19</td>\n",
       "      <td>None</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>10131248</th>\n",
       "      <td>15384723</td>\n",
       "      <td>2016-12-20</td>\n",
       "      <td>6</td>\n",
       "      <td>12322218</td>\n",
       "      <td>is a Continuation in part of</td>\n",
       "      <td>2009-01-29</td>\n",
       "      <td>2029-01-29</td>\n",
       "      <td>0</td>\n",
       "      <td>2029-01-29</td>\n",
       "      <td>2018-04-26</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>10153116</th>\n",
       "      <td>14647777</td>\n",
       "      <td>2015-05-27</td>\n",
       "      <td>2</td>\n",
       "      <td>PCT/US13/72596</td>\n",
       "      <td>is National Stage Entry of</td>\n",
       "      <td>2013-12-02</td>\n",
       "      <td>2033-12-02</td>\n",
       "      <td>0</td>\n",
       "      <td>2033-12-02</td>\n",
       "      <td>None</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>10166590</th>\n",
       "      <td>14865625</td>\n",
       "      <td>2015-09-25</td>\n",
       "      <td>0</td>\n",
       "      <td>14865625</td>\n",
       "      <td>Self</td>\n",
       "      <td>2015-09-25</td>\n",
       "      <td>2035-09-25</td>\n",
       "      <td>752</td>\n",
       "      <td>2037-10-16</td>\n",
       "      <td>None</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>10173739</th>\n",
       "      <td>15381456</td>\n",
       "      <td>2016-12-16</td>\n",
       "      <td>1</td>\n",
       "      <td>14839822</td>\n",
       "      <td>is a Continuation of</td>\n",
       "      <td>2015-08-28</td>\n",
       "      <td>2035-08-28</td>\n",
       "      <td>215</td>\n",
       "      <td>2036-03-30</td>\n",
       "      <td>None</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>10178805</th>\n",
       "      <td>14286670</td>\n",
       "      <td>2014-05-23</td>\n",
       "      <td>0</td>\n",
       "      <td>14286670</td>\n",
       "      <td>Self</td>\n",
       "      <td>2014-05-23</td>\n",
       "      <td>2034-05-23</td>\n",
       "      <td>339</td>\n",
       "      <td>2035-04-27</td>\n",
       "      <td>None</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "         application_number filing_date  number_of_parents  \\\n",
       "10011157           14803747  2015-07-20                  0   \n",
       "10018681           15002710  2016-01-21                  1   \n",
       "10019066           13765363  2013-02-12                  2   \n",
       "10023038           14703646  2015-05-04                  3   \n",
       "10046422           15099883  2016-04-15                  1   \n",
       "10131248           15384723  2016-12-20                  6   \n",
       "10153116           14647777  2015-05-27                  2   \n",
       "10166590           14865625  2015-09-25                  0   \n",
       "10173739           15381456  2016-12-16                  1   \n",
       "10178805           14286670  2014-05-23                  0   \n",
       "\n",
       "         earliest_parent_case  earliest_parent_relationship  \\\n",
       "10011157             14803747                          Self   \n",
       "10018681             15002710                          Self   \n",
       "10019066             13764942          is a Continuation of   \n",
       "10023038             13308300          is a Continuation of   \n",
       "10046422             13886672              is a Division of   \n",
       "10131248             12322218  is a Continuation in part of   \n",
       "10153116       PCT/US13/72596    is National Stage Entry of   \n",
       "10166590             14865625                          Self   \n",
       "10173739             14839822          is a Continuation of   \n",
       "10178805             14286670                          Self   \n",
       "\n",
       "         earliest_parent_filing_date 20_years_from_filing  PTA or PTE  \\\n",
       "10011157                  2015-07-20           2035-07-20         379   \n",
       "10018681                  2016-01-21           2036-01-21         370   \n",
       "10019066                  2013-02-12           2033-02-12         544   \n",
       "10023038                  2011-11-30           2031-11-30           0   \n",
       "10046422                  2013-05-03           2033-05-03         320   \n",
       "10131248                  2009-01-29           2029-01-29           0   \n",
       "10153116                  2013-12-02           2033-12-02           0   \n",
       "10166590                  2015-09-25           2035-09-25         752   \n",
       "10173739                  2015-08-28           2035-08-28         215   \n",
       "10178805                  2014-05-23           2034-05-23         339   \n",
       "\n",
       "         extended_expiration_date terminal_disclaimer_filed  \n",
       "10011157               2036-08-02                      None  \n",
       "10018681               2037-01-25                      None  \n",
       "10019066               2034-08-10                2018-03-05  \n",
       "10023038               2031-11-30                      None  \n",
       "10046422               2034-03-19                      None  \n",
       "10131248               2029-01-29                2018-04-26  \n",
       "10153116               2033-12-02                      None  \n",
       "10166590               2037-10-16                      None  \n",
       "10173739               2036-03-30                      None  \n",
       "10178805               2035-04-27                      None  "
      ]
     },
     "execution_count": 31,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "def terminal_disclaimer_present(app):\n",
    "    transactions = app.transaction_history\n",
    "    try:\n",
    "        disclaimer = next(t for t in transactions if t.code == 'DIST')\n",
    "        return disclaimer.date\n",
    "    except StopIteration:\n",
    "        return None\n",
    "    \n",
    "expiry_df['terminal_disclaimer_filed'] = [terminal_disclaimer_present(p) for p in patents]\n",
    "expiry_df.sort_index().head(10)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "We can put this all together as:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 30,
   "metadata": {},
   "outputs": [
    {
     "data": {
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       "      <th>8807637</th>\n",
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       "      <td>is a Division of</td>\n",
       "      <td>2010-09-22</td>\n",
       "      <td>2030-09-22</td>\n",
       "      <td>595</td>\n",
       "      <td>2030-09-22</td>\n",
       "      <td>2032-05-09</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9103143</th>\n",
       "      <td>13626864</td>\n",
       "      <td>2012-09-25</td>\n",
       "      <td>4</td>\n",
       "      <td>13626864</td>\n",
       "      <td>Self</td>\n",
       "      <td>2012-09-25</td>\n",
       "      <td>2032-09-25</td>\n",
       "      <td>413</td>\n",
       "      <td>2032-09-25</td>\n",
       "      <td>2033-11-12</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9151089</th>\n",
       "      <td>13627903</td>\n",
       "      <td>2012-09-26</td>\n",
       "      <td>4</td>\n",
       "      <td>13627903</td>\n",
       "      <td>Self</td>\n",
       "      <td>2012-09-26</td>\n",
       "      <td>2032-09-26</td>\n",
       "      <td>372</td>\n",
       "      <td>2032-09-26</td>\n",
       "      <td>2033-10-03</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>8807807</th>\n",
       "      <td>13628034</td>\n",
       "      <td>2012-09-26</td>\n",
       "      <td>4</td>\n",
       "      <td>13628034</td>\n",
       "      <td>Self</td>\n",
       "      <td>2012-09-26</td>\n",
       "      <td>2032-09-26</td>\n",
       "      <td>199</td>\n",
       "      <td>2032-09-26</td>\n",
       "      <td>2033-04-13</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "        application_number filing_date  number_of_parents  \\\n",
       "8807637           13621943  2012-09-18                  1   \n",
       "9209631           13624900  2012-09-22                  2   \n",
       "9103143           13626864  2012-09-25                  4   \n",
       "9151089           13627903  2012-09-26                  4   \n",
       "8807807           13628034  2012-09-26                  4   \n",
       "\n",
       "        earliest_parent_case earliest_parent_relationship  \\\n",
       "8807637             13621943                         Self   \n",
       "9209631             12887557             is a Division of   \n",
       "9103143             13626864                         Self   \n",
       "9151089             13627903                         Self   \n",
       "8807807             13628034                         Self   \n",
       "\n",
       "        earliest_parent_filing_date 20_years_from_filing  pta_or_pte  \\\n",
       "8807637                  2012-09-18           2032-09-18           0   \n",
       "9209631                  2010-09-22           2030-09-22         595   \n",
       "9103143                  2012-09-25           2032-09-25         413   \n",
       "9151089                  2012-09-26           2032-09-26         372   \n",
       "8807807                  2012-09-26           2032-09-26         199   \n",
       "\n",
       "        20_years_from_earliest_parent extended_expiration_date  \n",
       "8807637                    2032-09-18               2032-09-18  \n",
       "9209631                    2030-09-22               2032-05-09  \n",
       "9103143                    2032-09-25               2033-11-12  \n",
       "9151089                    2032-09-26               2033-10-03  \n",
       "8807807                    2032-09-26               2033-04-13  "
      ]
     },
     "execution_count": 30,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "from dateutil.relativedelta import relativedelta\n",
    "\n",
    "\n",
    "class Relationship():\n",
    "    pass\n",
    "\n",
    "def earliest_term_parent(app):\n",
    "    parents = app.parents\n",
    "    term_parents = [p for p in parents \n",
    "                    if p.relationship not in [\n",
    "                        'Claims Priority from Provisional Application',\n",
    "                        'is a Reissue of'\n",
    "                    ]]\n",
    "    if not term_parents:\n",
    "        # Create a dummy relationship if there are no matching relationships\n",
    "        earliest_parent = Relationship()\n",
    "        earliest_parent.filing_date = app.app_filing_date\n",
    "        earliest_parent.relationship = 'Self'\n",
    "        earliest_parent.appl_id = app.appl_id\n",
    "        return earliest_parent\n",
    "    earliest_parent = sorted(term_parents, key=lambda x: x.filing_date)[0]\n",
    "    return earliest_parent\n",
    "\n",
    "earliest_parents = [earliest_term_parent(p) for p in patents]\n",
    "\n",
    "expiration_df = pd.DataFrame(data={\n",
    "    'application_number': [a.appl_id for a in patents],\n",
    "    'filing_date': [a.app_filing_date for a in patents],\n",
    "    'number_of_parents': [len(p.parents) for p in patents],\n",
    "    'earliest_parent_case': [p.appl_id for p in earliest_parents],\n",
    "    'earliest_parent_relationship': [p.relationship for p in earliest_parents],\n",
    "    'earliest_parent_filing_date': [p.filing_date for p in earliest_parents],\n",
    "    '20_years_from_filing': [p.filing_date + relativedelta(years=20) for p in earliest_parents],\n",
    "    'pta_or_pte': [p.pta_pte_summary.total_days for p in patents],\n",
    "}, index=[a.patent_number for a in patents])\n",
    "\n",
    "expiration_df['20_years_from_earliest_parent'] = expiration_df['earliest_parent_filing_date'].apply(lambda x: x + relativedelta(years=20))\n",
    "expiration_df['extended_expiration_date'] = expiration_df.apply(lambda x: x['20_years_from_earliest_parent'] + relativedelta(days=x['pta_or_pte']), axis=1)\n",
    "\n",
    "expiration_df.head()"
   ]
  }
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