From 84d56ecf887f3b5279c18bf33654b14a368d6288 Mon Sep 17 00:00:00 2001
From: Konstantin Stadler <konstantin.stadler@ntnu.no>
Date: Fri, 5 Apr 2024 18:20:04 +0200
Subject: [PATCH] continued notebook extraction description

---
 doc/source/notebooks/extract_data.ipynb | 1017 ++++++++++++++++++++++-
 doc/source/notebooks/extract_data.py    |   98 ++-
 pymrio/core/mriosystem.py               |    2 +-
 3 files changed, 1089 insertions(+), 28 deletions(-)

diff --git a/doc/source/notebooks/extract_data.ipynb b/doc/source/notebooks/extract_data.ipynb
index faee60e7..59978606 100644
--- a/doc/source/notebooks/extract_data.ipynb
+++ b/doc/source/notebooks/extract_data.ipynb
@@ -13,28 +13,12 @@
    "id": "bcb8ce71-6b45-4ccc-81ad-866bc0d6c6f8",
    "metadata": {},
    "source": [
-    "This notebook shows how to extract specific data from the pymrio object for further processing in Python. For exporting/saving the data to another file format [see the Notebook on loading/saving/exporting](./load_save_export.ipynb)."
+    "This notebook shows how to extract specific data from the pymrio object for further processing in Python. For exporting/saving the data to another file format see [the notebook on saving/loading/exporting data.](./load_save_export.ipynb)"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
-   "id": "564fd5e1-8a3f-449a-9759-d36aa83473ce",
-   "metadata": {},
-   "outputs": [],
-   "source": []
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "id": "04097807-b375-42eb-b5c8-d0c457502a70",
-   "metadata": {},
-   "outputs": [],
-   "source": []
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 1,
+   "execution_count": 39,
    "id": "4f298de3-3641-44bb-88bb-c428d9cf5693",
    "metadata": {
     "tags": []
@@ -46,23 +30,1012 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 2,
+   "execution_count": 40,
    "id": "a38719d5-011c-4dff-969e-f915a205fd44",
    "metadata": {
     "tags": []
    },
    "outputs": [],
    "source": [
-    "mrio = pymrio.load_test()"
+    "mrio = pymrio.load_test().calc_all()\n",
+    "\n",
+    "### Basic pandas indexing of pymrio tables"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "f50f0173",
+   "metadata": {},
+   "source": [
+    "Since pymrio is built on top of pandas, we can use the pandas functions to extract data from the pymrio object. For example, to access the part of the A matrix from the region 2 we can use:"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 41,
    "id": "f6aadba4-ef17-40d2-aaec-845e274026b7",
    "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/html": [
+       "<div>\n",
+       "<style scoped>\n",
+       "    .dataframe tbody tr th:only-of-type {\n",
+       "        vertical-align: middle;\n",
+       "    }\n",
+       "\n",
+       "    .dataframe tbody tr th {\n",
+       "        vertical-align: top;\n",
+       "    }\n",
+       "\n",
+       "    .dataframe thead th {\n",
+       "        text-align: right;\n",
+       "    }\n",
+       "</style>\n",
+       "<table border=\"1\" class=\"dataframe\">\n",
+       "  <thead>\n",
+       "    <tr style=\"text-align: right;\">\n",
+       "      <th>sector</th>\n",
+       "      <th>food</th>\n",
+       "      <th>mining</th>\n",
+       "      <th>manufactoring</th>\n",
+       "      <th>electricity</th>\n",
+       "      <th>construction</th>\n",
+       "      <th>trade</th>\n",
+       "      <th>transport</th>\n",
+       "      <th>other</th>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>sector</th>\n",
+       "      <th></th>\n",
+       "      <th></th>\n",
+       "      <th></th>\n",
+       "      <th></th>\n",
+       "      <th></th>\n",
+       "      <th></th>\n",
+       "      <th></th>\n",
+       "      <th></th>\n",
+       "    </tr>\n",
+       "  </thead>\n",
+       "  <tbody>\n",
+       "    <tr>\n",
+       "      <th>food</th>\n",
+       "      <td>0.000486</td>\n",
+       "      <td>0.000638</td>\n",
+       "      <td>0.000194</td>\n",
+       "      <td>0.000005</td>\n",
+       "      <td>0.000019</td>\n",
+       "      <td>0.000092</td>\n",
+       "      <td>0.000027</td>\n",
+       "      <td>0.000026</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>mining</th>\n",
+       "      <td>0.000006</td>\n",
+       "      <td>0.050904</td>\n",
+       "      <td>0.000047</td>\n",
+       "      <td>0.000218</td>\n",
+       "      <td>0.000203</td>\n",
+       "      <td>0.000011</td>\n",
+       "      <td>0.000010</td>\n",
+       "      <td>0.000013</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>manufactoring</th>\n",
+       "      <td>0.000488</td>\n",
+       "      <td>0.069862</td>\n",
+       "      <td>0.001529</td>\n",
+       "      <td>0.000196</td>\n",
+       "      <td>0.005915</td>\n",
+       "      <td>0.001191</td>\n",
+       "      <td>0.002294</td>\n",
+       "      <td>0.000844</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>electricity</th>\n",
+       "      <td>0.000089</td>\n",
+       "      <td>0.050427</td>\n",
+       "      <td>0.000137</td>\n",
+       "      <td>0.000604</td>\n",
+       "      <td>0.000146</td>\n",
+       "      <td>0.000177</td>\n",
+       "      <td>0.000280</td>\n",
+       "      <td>0.000248</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>construction</th>\n",
+       "      <td>0.000025</td>\n",
+       "      <td>0.007375</td>\n",
+       "      <td>0.000032</td>\n",
+       "      <td>0.000109</td>\n",
+       "      <td>0.004615</td>\n",
+       "      <td>0.000088</td>\n",
+       "      <td>0.000515</td>\n",
+       "      <td>0.000422</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>trade</th>\n",
+       "      <td>0.000251</td>\n",
+       "      <td>0.028770</td>\n",
+       "      <td>0.000531</td>\n",
+       "      <td>0.000095</td>\n",
+       "      <td>0.001640</td>\n",
+       "      <td>0.000772</td>\n",
+       "      <td>0.001372</td>\n",
+       "      <td>0.000487</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>transport</th>\n",
+       "      <td>0.000071</td>\n",
+       "      <td>0.031839</td>\n",
+       "      <td>0.000212</td>\n",
+       "      <td>0.000069</td>\n",
+       "      <td>0.000714</td>\n",
+       "      <td>0.000579</td>\n",
+       "      <td>0.004747</td>\n",
+       "      <td>0.000494</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>other</th>\n",
+       "      <td>0.000171</td>\n",
+       "      <td>0.064935</td>\n",
+       "      <td>0.000595</td>\n",
+       "      <td>0.000291</td>\n",
+       "      <td>0.002844</td>\n",
+       "      <td>0.001897</td>\n",
+       "      <td>0.003800</td>\n",
+       "      <td>0.003936</td>\n",
+       "    </tr>\n",
+       "  </tbody>\n",
+       "</table>\n",
+       "</div>"
+      ],
+      "text/plain": [
+       "sector             food    mining  manufactoring  electricity  construction  \\\n",
+       "sector                                                                        \n",
+       "food           0.000486  0.000638       0.000194     0.000005      0.000019   \n",
+       "mining         0.000006  0.050904       0.000047     0.000218      0.000203   \n",
+       "manufactoring  0.000488  0.069862       0.001529     0.000196      0.005915   \n",
+       "electricity    0.000089  0.050427       0.000137     0.000604      0.000146   \n",
+       "construction   0.000025  0.007375       0.000032     0.000109      0.004615   \n",
+       "trade          0.000251  0.028770       0.000531     0.000095      0.001640   \n",
+       "transport      0.000071  0.031839       0.000212     0.000069      0.000714   \n",
+       "other          0.000171  0.064935       0.000595     0.000291      0.002844   \n",
+       "\n",
+       "sector            trade  transport     other  \n",
+       "sector                                        \n",
+       "food           0.000092   0.000027  0.000026  \n",
+       "mining         0.000011   0.000010  0.000013  \n",
+       "manufactoring  0.001191   0.002294  0.000844  \n",
+       "electricity    0.000177   0.000280  0.000248  \n",
+       "construction   0.000088   0.000515  0.000422  \n",
+       "trade          0.000772   0.001372  0.000487  \n",
+       "transport      0.000579   0.004747  0.000494  \n",
+       "other          0.001897   0.003800  0.003936  "
+      ]
+     },
+     "execution_count": 41,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "A_reg2 = mrio.A.loc[\"reg2\", \"reg2\"]\n",
+    "A_reg2"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "1a9e6bcd",
+   "metadata": {
+    "lines_to_next_cell": 2
+   },
+   "source": [
+    "Most tables are indexed via a multiindex, in case of the A matrix the index is a tuple of the region and the sector.\n",
+    "To access all technical coefficients (column) data for mining from all regions we can use:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 42,
+   "id": "bdc4c511",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/html": [
+       "<div>\n",
+       "<style scoped>\n",
+       "    .dataframe tbody tr th:only-of-type {\n",
+       "        vertical-align: middle;\n",
+       "    }\n",
+       "\n",
+       "    .dataframe tbody tr th {\n",
+       "        vertical-align: top;\n",
+       "    }\n",
+       "\n",
+       "    .dataframe thead tr th {\n",
+       "        text-align: left;\n",
+       "    }\n",
+       "\n",
+       "    .dataframe thead tr:last-of-type th {\n",
+       "        text-align: right;\n",
+       "    }\n",
+       "</style>\n",
+       "<table border=\"1\" class=\"dataframe\">\n",
+       "  <thead>\n",
+       "    <tr>\n",
+       "      <th></th>\n",
+       "      <th>region</th>\n",
+       "      <th>reg1</th>\n",
+       "      <th>reg2</th>\n",
+       "      <th>reg3</th>\n",
+       "      <th>reg4</th>\n",
+       "      <th>reg5</th>\n",
+       "      <th>reg6</th>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th></th>\n",
+       "      <th>sector</th>\n",
+       "      <th>mining</th>\n",
+       "      <th>mining</th>\n",
+       "      <th>mining</th>\n",
+       "      <th>mining</th>\n",
+       "      <th>mining</th>\n",
+       "      <th>mining</th>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>region</th>\n",
+       "      <th>sector</th>\n",
+       "      <th></th>\n",
+       "      <th></th>\n",
+       "      <th></th>\n",
+       "      <th></th>\n",
+       "      <th></th>\n",
+       "      <th></th>\n",
+       "    </tr>\n",
+       "  </thead>\n",
+       "  <tbody>\n",
+       "    <tr>\n",
+       "      <th rowspan=\"8\" valign=\"top\">reg1</th>\n",
+       "      <th>food</th>\n",
+       "      <td>0.001179</td>\n",
+       "      <td>0.000010</td>\n",
+       "      <td>3.652734e-09</td>\n",
+       "      <td>1.626677e-06</td>\n",
+       "      <td>3.767567e-07</td>\n",
+       "      <td>1.481621e-05</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>mining</th>\n",
+       "      <td>0.048022</td>\n",
+       "      <td>0.000268</td>\n",
+       "      <td>7.486558e-07</td>\n",
+       "      <td>6.899387e-05</td>\n",
+       "      <td>3.628651e-05</td>\n",
+       "      <td>8.801658e-05</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>manufactoring</th>\n",
+       "      <td>0.124366</td>\n",
+       "      <td>0.017417</td>\n",
+       "      <td>2.799765e-05</td>\n",
+       "      <td>9.161688e-03</td>\n",
+       "      <td>4.792741e-03</td>\n",
+       "      <td>2.087445e-03</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>electricity</th>\n",
+       "      <td>0.037991</td>\n",
+       "      <td>0.001099</td>\n",
+       "      <td>2.170169e-07</td>\n",
+       "      <td>1.150382e-08</td>\n",
+       "      <td>1.444660e-05</td>\n",
+       "      <td>8.892062e-06</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>construction</th>\n",
+       "      <td>0.017324</td>\n",
+       "      <td>0.000022</td>\n",
+       "      <td>8.884210e-08</td>\n",
+       "      <td>1.331990e-07</td>\n",
+       "      <td>1.129186e-05</td>\n",
+       "      <td>7.641830e-07</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>trade</th>\n",
+       "      <td>0.035429</td>\n",
+       "      <td>0.001836</td>\n",
+       "      <td>6.170323e-07</td>\n",
+       "      <td>3.835340e-04</td>\n",
+       "      <td>1.071471e-03</td>\n",
+       "      <td>5.575273e-04</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>transport</th>\n",
+       "      <td>0.060324</td>\n",
+       "      <td>0.001544</td>\n",
+       "      <td>4.060594e-06</td>\n",
+       "      <td>5.820972e-04</td>\n",
+       "      <td>1.278089e-03</td>\n",
+       "      <td>6.555200e-03</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>other</th>\n",
+       "      <td>0.092059</td>\n",
+       "      <td>0.005024</td>\n",
+       "      <td>1.788858e-05</td>\n",
+       "      <td>3.664017e-04</td>\n",
+       "      <td>7.664473e-04</td>\n",
+       "      <td>3.287131e-04</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th rowspan=\"8\" valign=\"top\">reg2</th>\n",
+       "      <th>food</th>\n",
+       "      <td>0.000084</td>\n",
+       "      <td>0.000638</td>\n",
+       "      <td>3.772203e-09</td>\n",
+       "      <td>2.165695e-07</td>\n",
+       "      <td>9.237430e-08</td>\n",
+       "      <td>3.105702e-05</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>mining</th>\n",
+       "      <td>0.000523</td>\n",
+       "      <td>0.050904</td>\n",
+       "      <td>5.883755e-06</td>\n",
+       "      <td>5.472492e-05</td>\n",
+       "      <td>2.212937e-05</td>\n",
+       "      <td>3.108304e-05</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>manufactoring</th>\n",
+       "      <td>0.014563</td>\n",
+       "      <td>0.069862</td>\n",
+       "      <td>1.223889e-05</td>\n",
+       "      <td>4.170428e-03</td>\n",
+       "      <td>2.164157e-03</td>\n",
+       "      <td>1.355740e-03</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>electricity</th>\n",
+       "      <td>0.000430</td>\n",
+       "      <td>0.050427</td>\n",
+       "      <td>1.143580e-08</td>\n",
+       "      <td>2.061508e-08</td>\n",
+       "      <td>3.266417e-06</td>\n",
+       "      <td>3.535380e-07</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>construction</th>\n",
+       "      <td>0.000050</td>\n",
+       "      <td>0.007375</td>\n",
+       "      <td>1.666888e-07</td>\n",
+       "      <td>1.910407e-07</td>\n",
+       "      <td>1.702833e-05</td>\n",
+       "      <td>1.421644e-06</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>trade</th>\n",
+       "      <td>0.000769</td>\n",
+       "      <td>0.028770</td>\n",
+       "      <td>1.092766e-06</td>\n",
+       "      <td>1.792846e-04</td>\n",
+       "      <td>1.000066e-03</td>\n",
+       "      <td>3.103879e-04</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>transport</th>\n",
+       "      <td>0.003095</td>\n",
+       "      <td>0.031839</td>\n",
+       "      <td>1.993361e-06</td>\n",
+       "      <td>2.990600e-05</td>\n",
+       "      <td>1.294761e-03</td>\n",
+       "      <td>1.368746e-03</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>other</th>\n",
+       "      <td>0.001584</td>\n",
+       "      <td>0.064935</td>\n",
+       "      <td>2.418065e-05</td>\n",
+       "      <td>2.702272e-04</td>\n",
+       "      <td>4.571674e-04</td>\n",
+       "      <td>3.392091e-04</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th rowspan=\"8\" valign=\"top\">reg3</th>\n",
+       "      <th>food</th>\n",
+       "      <td>0.000037</td>\n",
+       "      <td>0.000005</td>\n",
+       "      <td>1.309056e-05</td>\n",
+       "      <td>6.378397e-06</td>\n",
+       "      <td>4.673894e-07</td>\n",
+       "      <td>3.461944e-06</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>mining</th>\n",
+       "      <td>0.000396</td>\n",
+       "      <td>0.000151</td>\n",
+       "      <td>4.337922e-04</td>\n",
+       "      <td>3.495268e-04</td>\n",
+       "      <td>1.564949e-04</td>\n",
+       "      <td>4.882839e-05</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>manufactoring</th>\n",
+       "      <td>0.007782</td>\n",
+       "      <td>0.003842</td>\n",
+       "      <td>6.572771e-04</td>\n",
+       "      <td>5.043959e-03</td>\n",
+       "      <td>3.621657e-03</td>\n",
+       "      <td>1.629835e-03</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>electricity</th>\n",
+       "      <td>0.000045</td>\n",
+       "      <td>0.000107</td>\n",
+       "      <td>2.495370e-04</td>\n",
+       "      <td>1.401577e-04</td>\n",
+       "      <td>5.464145e-07</td>\n",
+       "      <td>1.165971e-05</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>construction</th>\n",
+       "      <td>0.000006</td>\n",
+       "      <td>0.000003</td>\n",
+       "      <td>2.786913e-04</td>\n",
+       "      <td>2.624508e-07</td>\n",
+       "      <td>6.239448e-06</td>\n",
+       "      <td>1.237150e-08</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>trade</th>\n",
+       "      <td>0.000150</td>\n",
+       "      <td>0.000060</td>\n",
+       "      <td>2.485529e-04</td>\n",
+       "      <td>4.141811e-05</td>\n",
+       "      <td>1.517855e-03</td>\n",
+       "      <td>2.062017e-03</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>transport</th>\n",
+       "      <td>0.001768</td>\n",
+       "      <td>0.000618</td>\n",
+       "      <td>2.091958e-04</td>\n",
+       "      <td>4.965269e-04</td>\n",
+       "      <td>3.777028e-04</td>\n",
+       "      <td>2.449723e-03</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>other</th>\n",
+       "      <td>0.002269</td>\n",
+       "      <td>0.007583</td>\n",
+       "      <td>1.861799e-03</td>\n",
+       "      <td>2.275626e-03</td>\n",
+       "      <td>2.430304e-03</td>\n",
+       "      <td>1.329935e-03</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th rowspan=\"8\" valign=\"top\">reg4</th>\n",
+       "      <th>food</th>\n",
+       "      <td>0.000171</td>\n",
+       "      <td>0.000578</td>\n",
+       "      <td>6.340547e-10</td>\n",
+       "      <td>1.413307e-03</td>\n",
+       "      <td>1.378513e-07</td>\n",
+       "      <td>2.636256e-05</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>mining</th>\n",
+       "      <td>0.000311</td>\n",
+       "      <td>0.002467</td>\n",
+       "      <td>2.719214e-05</td>\n",
+       "      <td>6.138652e-02</td>\n",
+       "      <td>1.552800e-04</td>\n",
+       "      <td>2.699482e-04</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>manufactoring</th>\n",
+       "      <td>0.005207</td>\n",
+       "      <td>0.003579</td>\n",
+       "      <td>4.405268e-05</td>\n",
+       "      <td>1.493263e-01</td>\n",
+       "      <td>2.139451e-03</td>\n",
+       "      <td>2.578051e-03</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>electricity</th>\n",
+       "      <td>0.000081</td>\n",
+       "      <td>0.000013</td>\n",
+       "      <td>1.295279e-06</td>\n",
+       "      <td>4.967797e-02</td>\n",
+       "      <td>1.543713e-08</td>\n",
+       "      <td>1.669269e-05</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>construction</th>\n",
+       "      <td>0.000021</td>\n",
+       "      <td>0.000008</td>\n",
+       "      <td>6.055807e-07</td>\n",
+       "      <td>2.337226e-03</td>\n",
+       "      <td>7.889622e-06</td>\n",
+       "      <td>2.033545e-06</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>trade</th>\n",
+       "      <td>0.000005</td>\n",
+       "      <td>0.000016</td>\n",
+       "      <td>1.595023e-07</td>\n",
+       "      <td>2.826377e-02</td>\n",
+       "      <td>9.701854e-05</td>\n",
+       "      <td>7.025049e-04</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>transport</th>\n",
+       "      <td>0.000356</td>\n",
+       "      <td>0.000048</td>\n",
+       "      <td>9.595997e-07</td>\n",
+       "      <td>1.586496e-02</td>\n",
+       "      <td>3.012550e-04</td>\n",
+       "      <td>1.991747e-03</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>other</th>\n",
+       "      <td>0.000873</td>\n",
+       "      <td>0.000958</td>\n",
+       "      <td>6.314447e-06</td>\n",
+       "      <td>4.648443e-02</td>\n",
+       "      <td>1.117863e-04</td>\n",
+       "      <td>6.261181e-04</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th rowspan=\"8\" valign=\"top\">reg5</th>\n",
+       "      <th>food</th>\n",
+       "      <td>0.000062</td>\n",
+       "      <td>0.000028</td>\n",
+       "      <td>1.108149e-07</td>\n",
+       "      <td>1.524618e-05</td>\n",
+       "      <td>1.996382e-04</td>\n",
+       "      <td>2.327498e-05</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>mining</th>\n",
+       "      <td>0.003143</td>\n",
+       "      <td>0.001784</td>\n",
+       "      <td>2.499451e-06</td>\n",
+       "      <td>1.013051e-03</td>\n",
+       "      <td>5.149154e-02</td>\n",
+       "      <td>9.996927e-04</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>manufactoring</th>\n",
+       "      <td>0.004680</td>\n",
+       "      <td>0.002365</td>\n",
+       "      <td>1.612636e-05</td>\n",
+       "      <td>5.466745e-04</td>\n",
+       "      <td>8.061924e-02</td>\n",
+       "      <td>1.405121e-03</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>electricity</th>\n",
+       "      <td>0.000956</td>\n",
+       "      <td>0.000018</td>\n",
+       "      <td>5.676661e-08</td>\n",
+       "      <td>2.164907e-06</td>\n",
+       "      <td>2.545719e-02</td>\n",
+       "      <td>1.096431e-05</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>construction</th>\n",
+       "      <td>0.000071</td>\n",
+       "      <td>0.000034</td>\n",
+       "      <td>5.621276e-07</td>\n",
+       "      <td>3.027990e-08</td>\n",
+       "      <td>1.765549e-02</td>\n",
+       "      <td>3.883278e-06</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>trade</th>\n",
+       "      <td>0.000149</td>\n",
+       "      <td>0.000639</td>\n",
+       "      <td>1.895713e-06</td>\n",
+       "      <td>5.016841e-05</td>\n",
+       "      <td>4.981458e-02</td>\n",
+       "      <td>1.014394e-03</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>transport</th>\n",
+       "      <td>0.001154</td>\n",
+       "      <td>0.000820</td>\n",
+       "      <td>2.183364e-06</td>\n",
+       "      <td>2.255475e-05</td>\n",
+       "      <td>3.801613e-02</td>\n",
+       "      <td>2.591267e-03</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>other</th>\n",
+       "      <td>0.000347</td>\n",
+       "      <td>0.000512</td>\n",
+       "      <td>4.026853e-06</td>\n",
+       "      <td>9.871058e-05</td>\n",
+       "      <td>6.984674e-02</td>\n",
+       "      <td>5.676656e-04</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th rowspan=\"8\" valign=\"top\">reg6</th>\n",
+       "      <th>food</th>\n",
+       "      <td>0.000143</td>\n",
+       "      <td>0.000093</td>\n",
+       "      <td>1.099390e-07</td>\n",
+       "      <td>6.355405e-05</td>\n",
+       "      <td>1.119791e-06</td>\n",
+       "      <td>6.959613e-04</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>mining</th>\n",
+       "      <td>0.007456</td>\n",
+       "      <td>0.005567</td>\n",
+       "      <td>3.220657e-05</td>\n",
+       "      <td>2.052196e-03</td>\n",
+       "      <td>9.791972e-04</td>\n",
+       "      <td>1.512044e-01</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>manufactoring</th>\n",
+       "      <td>0.005841</td>\n",
+       "      <td>0.005784</td>\n",
+       "      <td>2.046172e-05</td>\n",
+       "      <td>2.154067e-03</td>\n",
+       "      <td>6.448726e-03</td>\n",
+       "      <td>5.043697e-02</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>electricity</th>\n",
+       "      <td>0.000197</td>\n",
+       "      <td>0.000168</td>\n",
+       "      <td>1.470729e-07</td>\n",
+       "      <td>1.102498e-05</td>\n",
+       "      <td>3.010193e-05</td>\n",
+       "      <td>6.787911e-03</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>construction</th>\n",
+       "      <td>0.000038</td>\n",
+       "      <td>0.000023</td>\n",
+       "      <td>5.264129e-07</td>\n",
+       "      <td>5.950288e-07</td>\n",
+       "      <td>3.829687e-05</td>\n",
+       "      <td>2.041605e-03</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>trade</th>\n",
+       "      <td>0.000209</td>\n",
+       "      <td>0.000184</td>\n",
+       "      <td>6.734943e-07</td>\n",
+       "      <td>1.334155e-04</td>\n",
+       "      <td>1.324385e-04</td>\n",
+       "      <td>4.701872e-03</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>transport</th>\n",
+       "      <td>0.002636</td>\n",
+       "      <td>0.002308</td>\n",
+       "      <td>4.652734e-06</td>\n",
+       "      <td>4.705530e-05</td>\n",
+       "      <td>2.978642e-04</td>\n",
+       "      <td>4.032717e-02</td>\n",
+       "    </tr>\n",
+       "    <tr>\n",
+       "      <th>other</th>\n",
+       "      <td>0.000505</td>\n",
+       "      <td>0.000804</td>\n",
+       "      <td>3.262233e-06</td>\n",
+       "      <td>2.790342e-04</td>\n",
+       "      <td>2.084267e-04</td>\n",
+       "      <td>2.052462e-02</td>\n",
+       "    </tr>\n",
+       "  </tbody>\n",
+       "</table>\n",
+       "</div>"
+      ],
+      "text/plain": [
+       "region                    reg1      reg2          reg3          reg4  \\\n",
+       "sector                  mining    mining        mining        mining   \n",
+       "region sector                                                          \n",
+       "reg1   food           0.001179  0.000010  3.652734e-09  1.626677e-06   \n",
+       "       mining         0.048022  0.000268  7.486558e-07  6.899387e-05   \n",
+       "       manufactoring  0.124366  0.017417  2.799765e-05  9.161688e-03   \n",
+       "       electricity    0.037991  0.001099  2.170169e-07  1.150382e-08   \n",
+       "       construction   0.017324  0.000022  8.884210e-08  1.331990e-07   \n",
+       "       trade          0.035429  0.001836  6.170323e-07  3.835340e-04   \n",
+       "       transport      0.060324  0.001544  4.060594e-06  5.820972e-04   \n",
+       "       other          0.092059  0.005024  1.788858e-05  3.664017e-04   \n",
+       "reg2   food           0.000084  0.000638  3.772203e-09  2.165695e-07   \n",
+       "       mining         0.000523  0.050904  5.883755e-06  5.472492e-05   \n",
+       "       manufactoring  0.014563  0.069862  1.223889e-05  4.170428e-03   \n",
+       "       electricity    0.000430  0.050427  1.143580e-08  2.061508e-08   \n",
+       "       construction   0.000050  0.007375  1.666888e-07  1.910407e-07   \n",
+       "       trade          0.000769  0.028770  1.092766e-06  1.792846e-04   \n",
+       "       transport      0.003095  0.031839  1.993361e-06  2.990600e-05   \n",
+       "       other          0.001584  0.064935  2.418065e-05  2.702272e-04   \n",
+       "reg3   food           0.000037  0.000005  1.309056e-05  6.378397e-06   \n",
+       "       mining         0.000396  0.000151  4.337922e-04  3.495268e-04   \n",
+       "       manufactoring  0.007782  0.003842  6.572771e-04  5.043959e-03   \n",
+       "       electricity    0.000045  0.000107  2.495370e-04  1.401577e-04   \n",
+       "       construction   0.000006  0.000003  2.786913e-04  2.624508e-07   \n",
+       "       trade          0.000150  0.000060  2.485529e-04  4.141811e-05   \n",
+       "       transport      0.001768  0.000618  2.091958e-04  4.965269e-04   \n",
+       "       other          0.002269  0.007583  1.861799e-03  2.275626e-03   \n",
+       "reg4   food           0.000171  0.000578  6.340547e-10  1.413307e-03   \n",
+       "       mining         0.000311  0.002467  2.719214e-05  6.138652e-02   \n",
+       "       manufactoring  0.005207  0.003579  4.405268e-05  1.493263e-01   \n",
+       "       electricity    0.000081  0.000013  1.295279e-06  4.967797e-02   \n",
+       "       construction   0.000021  0.000008  6.055807e-07  2.337226e-03   \n",
+       "       trade          0.000005  0.000016  1.595023e-07  2.826377e-02   \n",
+       "       transport      0.000356  0.000048  9.595997e-07  1.586496e-02   \n",
+       "       other          0.000873  0.000958  6.314447e-06  4.648443e-02   \n",
+       "reg5   food           0.000062  0.000028  1.108149e-07  1.524618e-05   \n",
+       "       mining         0.003143  0.001784  2.499451e-06  1.013051e-03   \n",
+       "       manufactoring  0.004680  0.002365  1.612636e-05  5.466745e-04   \n",
+       "       electricity    0.000956  0.000018  5.676661e-08  2.164907e-06   \n",
+       "       construction   0.000071  0.000034  5.621276e-07  3.027990e-08   \n",
+       "       trade          0.000149  0.000639  1.895713e-06  5.016841e-05   \n",
+       "       transport      0.001154  0.000820  2.183364e-06  2.255475e-05   \n",
+       "       other          0.000347  0.000512  4.026853e-06  9.871058e-05   \n",
+       "reg6   food           0.000143  0.000093  1.099390e-07  6.355405e-05   \n",
+       "       mining         0.007456  0.005567  3.220657e-05  2.052196e-03   \n",
+       "       manufactoring  0.005841  0.005784  2.046172e-05  2.154067e-03   \n",
+       "       electricity    0.000197  0.000168  1.470729e-07  1.102498e-05   \n",
+       "       construction   0.000038  0.000023  5.264129e-07  5.950288e-07   \n",
+       "       trade          0.000209  0.000184  6.734943e-07  1.334155e-04   \n",
+       "       transport      0.002636  0.002308  4.652734e-06  4.705530e-05   \n",
+       "       other          0.000505  0.000804  3.262233e-06  2.790342e-04   \n",
+       "\n",
+       "region                        reg5          reg6  \n",
+       "sector                      mining        mining  \n",
+       "region sector                                     \n",
+       "reg1   food           3.767567e-07  1.481621e-05  \n",
+       "       mining         3.628651e-05  8.801658e-05  \n",
+       "       manufactoring  4.792741e-03  2.087445e-03  \n",
+       "       electricity    1.444660e-05  8.892062e-06  \n",
+       "       construction   1.129186e-05  7.641830e-07  \n",
+       "       trade          1.071471e-03  5.575273e-04  \n",
+       "       transport      1.278089e-03  6.555200e-03  \n",
+       "       other          7.664473e-04  3.287131e-04  \n",
+       "reg2   food           9.237430e-08  3.105702e-05  \n",
+       "       mining         2.212937e-05  3.108304e-05  \n",
+       "       manufactoring  2.164157e-03  1.355740e-03  \n",
+       "       electricity    3.266417e-06  3.535380e-07  \n",
+       "       construction   1.702833e-05  1.421644e-06  \n",
+       "       trade          1.000066e-03  3.103879e-04  \n",
+       "       transport      1.294761e-03  1.368746e-03  \n",
+       "       other          4.571674e-04  3.392091e-04  \n",
+       "reg3   food           4.673894e-07  3.461944e-06  \n",
+       "       mining         1.564949e-04  4.882839e-05  \n",
+       "       manufactoring  3.621657e-03  1.629835e-03  \n",
+       "       electricity    5.464145e-07  1.165971e-05  \n",
+       "       construction   6.239448e-06  1.237150e-08  \n",
+       "       trade          1.517855e-03  2.062017e-03  \n",
+       "       transport      3.777028e-04  2.449723e-03  \n",
+       "       other          2.430304e-03  1.329935e-03  \n",
+       "reg4   food           1.378513e-07  2.636256e-05  \n",
+       "       mining         1.552800e-04  2.699482e-04  \n",
+       "       manufactoring  2.139451e-03  2.578051e-03  \n",
+       "       electricity    1.543713e-08  1.669269e-05  \n",
+       "       construction   7.889622e-06  2.033545e-06  \n",
+       "       trade          9.701854e-05  7.025049e-04  \n",
+       "       transport      3.012550e-04  1.991747e-03  \n",
+       "       other          1.117863e-04  6.261181e-04  \n",
+       "reg5   food           1.996382e-04  2.327498e-05  \n",
+       "       mining         5.149154e-02  9.996927e-04  \n",
+       "       manufactoring  8.061924e-02  1.405121e-03  \n",
+       "       electricity    2.545719e-02  1.096431e-05  \n",
+       "       construction   1.765549e-02  3.883278e-06  \n",
+       "       trade          4.981458e-02  1.014394e-03  \n",
+       "       transport      3.801613e-02  2.591267e-03  \n",
+       "       other          6.984674e-02  5.676656e-04  \n",
+       "reg6   food           1.119791e-06  6.959613e-04  \n",
+       "       mining         9.791972e-04  1.512044e-01  \n",
+       "       manufactoring  6.448726e-03  5.043697e-02  \n",
+       "       electricity    3.010193e-05  6.787911e-03  \n",
+       "       construction   3.829687e-05  2.041605e-03  \n",
+       "       trade          1.324385e-04  4.701872e-03  \n",
+       "       transport      2.978642e-04  4.032717e-02  \n",
+       "       other          2.084267e-04  2.052462e-02  "
+      ]
+     },
+     "execution_count": 42,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "A_mining = mrio.A.loc[:, (slice(None), \"mining\")]\n",
+    "A_mining"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "6b77959c",
+   "metadata": {},
+   "source": [
+    "For further information on the pandas multiindex see the [pandas documentation on advanced indexing.](https://pandas.pydata.org/docs/user_guide/advanced.html)\n",
+    "\n",
+    "## Extracting data across extension tables"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "6d77f052",
+   "metadata": {},
+   "source": [
+    "Pymrio includes methods for bulk extraction of data across extension tables. These can either work on a specific extension or across all extensions of the system."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "e9f1a370",
+   "metadata": {
+    "lines_to_next_cell": 2
+   },
+   "source": [
+    "### Extracting from a specific extension"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "9ec046cc",
+   "metadata": {},
+   "source": [
+    "Here we use use the `extract` method available in the extension object.\n",
+    "This expect a list of rows (index) to extract.\n",
+    "Here we extract some rows from the emission extension table.\n",
+    "To do so, we first define the rows (index) to extract:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 43,
+   "id": "debe154e",
+   "metadata": {},
    "outputs": [],
-   "source": []
+   "source": [
+    "rows_to_extract =[('emission_type1',   'air'),\n",
+    "                  ('emission_type2', 'water')]"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "8051fc37",
+   "metadata": {},
+   "source": [
+    "We can now use the `extract` method to extract the data, either as a pandas DataFrame"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 44,
+   "id": "c945af36",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "dict_keys(['F', 'F_Y', 'S', 'S_Y', 'M', 'M_down', 'D_cba', 'D_pba', 'D_imp', 'D_exp', 'unit', 'D_cba_reg', 'D_pba_reg', 'D_imp_reg', 'D_exp_reg', 'D_cba_cap', 'D_pba_cap', 'D_imp_cap', 'D_exp_cap'])"
+      ]
+     },
+     "execution_count": 44,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "df_extract = mrio.emissions.extract(rows_to_extract, return_type=\"dataframe\")\n",
+    "df_extract.keys()"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "a5aea0ad",
+   "metadata": {},
+   "source": [
+    "Or we extract into a new extension object:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 45,
+   "id": "8f596735",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "'Extension Emissions_extracted with parameters: name, F, F_Y, S, S_Y, M, M_down, D_cba, D_pba, D_imp, D_exp, unit, D_cba_reg, D_pba_reg, D_imp_reg, D_exp_reg, D_cba_cap, D_pba_cap, D_imp_cap, D_exp_cap'"
+      ]
+     },
+     "execution_count": 45,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "ext_extract = mrio.emissions.extract(rows_to_extract, return_type=\"extension\")\n",
+    "str(ext_extract)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "66981d62",
+   "metadata": {},
+   "source": [
+    "Note that the name of the extension object is now `Emissions_extracted`, based on the name of the original extension object.\n",
+    "To use another name, just pass the name as the `return_type` method."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 46,
+   "id": "c39cfc64",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "'Extension new_extension with parameters: name, F, F_Y, S, S_Y, M, M_down, D_cba, D_pba, D_imp, D_exp, unit, D_cba_reg, D_pba_reg, D_imp_reg, D_exp_reg, D_cba_cap, D_pba_cap, D_imp_cap, D_exp_cap'"
+      ]
+     },
+     "execution_count": 46,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "new_extension = mrio.emissions.extract(rows_to_extract, return_type=\"new_extension\")\n",
+    "str(new_extension)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "68f6f3e8",
+   "metadata": {},
+   "source": [
+    "Extracting to dataframes is also a convienient way to convert an extension object to a dictionary:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 47,
+   "id": "b23d7415",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "dict_keys(['F', 'F_Y', 'S', 'S_Y', 'M', 'M_down', 'D_cba', 'D_pba', 'D_imp', 'D_exp', 'unit', 'D_cba_reg', 'D_pba_reg', 'D_imp_reg', 'D_exp_reg', 'D_cba_cap', 'D_pba_cap', 'D_imp_cap', 'D_exp_cap'])"
+      ]
+     },
+     "execution_count": 47,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "df_all = mrio.emissions.extract(mrio.emissions.get_rows(), return_type=\"dfs\")\n",
+    "df_all.keys()"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "4357fd67",
+   "metadata": {
+    "lines_to_next_cell": 2
+   },
+   "source": [
+    "CONT: DESRIBE STUFF ABOVE\n",
+    "For example, to extract the total value added for all regions and sectors we can use:"
+   ]
   }
  ],
  "metadata": {
diff --git a/doc/source/notebooks/extract_data.py b/doc/source/notebooks/extract_data.py
index ebd0d99b..e37d9fd4 100644
--- a/doc/source/notebooks/extract_data.py
+++ b/doc/source/notebooks/extract_data.py
@@ -57,11 +57,99 @@
 # %% [markdown]
 # Here we use use the `extract` method available in the extension object.
 # This expect a list of rows (index) to extract.
+# Here we extract some rows from the emission extension table.
+# To do so, we first define the rows (index) to extract:
 
-row = mrio.emissions.get_rows()
+# %%
+rows_to_extract =[('emission_type1',   'air'),
+                  ('emission_type2', 'water')]
+
+# %% [markdown]
+# We can now use the `extract` method to extract the data, either as a pandas DataFrame
+
+# %%
+df_extract = mrio.emissions.extract(rows_to_extract, return_type="dataframe")
+df_extract.keys()
+
+# %% [markdown]
+# Or we extract into a new extension object:
+
+# %%
+ext_extract = mrio.emissions.extract(rows_to_extract, return_type="extension")
+str(ext_extract)
+
+# %% [markdown]
+# Note that the name of the extension object is now `Emissions_extracted`, based on the name of the original extension object.
+# To use another name, just pass the name as the `return_type` method.
 
-df_extract = mrio.emissions.extract(row, return_type="dataframe")
-ext_extract = mrio.emissions.extract(row, return_type="extension")
+# %% 
+new_extension = mrio.emissions.extract(rows_to_extract, return_type="new_extension")
+str(new_extension)
+
+# %% [markdown]
+# Extracting to dataframes is also a convienient 
+# way to convert an extension object to a dictionary:
+
+# %% 
+df_all = mrio.emissions.extract(mrio.emissions.get_rows(), return_type="dfs")
+df_all.keys()
+
+
+# The method also allows to only extract some of the accounts:
+df_some = mrio.emissions.extract(mrio.emissions.get_rows(), dataframes=['D_cba', 'D_pba'], return_type="dfs")
+df_some.keys()
+
+
+
+# %% [markdown]
+#### Extracting from all extensions
+
+# %% [markdown]
+# We can also extract data from all extensions at once. 
+# This is done using the `extension_extract` method from the pymrio object.
+# This expect a dict with keys based on the extension names and values as a list of rows (index) to extract.
+
+# %% [markdown]
+# Lets assume we want to extract value added and all emissions.
+# We first define the rows (index) to extract:
+
+# %%
+to_extract = {'Factor Inputs': 'Value Added',
+              'Emissions': [('emission_type1',   'air'),
+                            ('emission_type2', 'water')]}
+
+
+# %% [markdown]
+# And can then use the `extension_extract` method to extract the data, either as a pandas DataFrame, 
+# which returns a dictionary with the extension names as keys
+
+# %%
+df_extract_all = mrio.extension_extract(to_extract, return_type="dataframe")
+df_extract_all.keys()
+
+# %% 
+df_extract_all['Factor Inputs'].keys()
+
+# %% [markdown]
+# We can also extract into a dictionary of extension objects:
+
+# %%
+ext_extract_all = mrio.extension_extract(to_extract, return_type="extensions")
+ext_extract_all.keys()
+
+extracts = ext_extract_all 
+
+r = pymrio.concate_extension(*extracts.values(), name="abc")
+
+# %% 
+str(ext_extract_all['Factor Inputs'])
+
+# %% [markdown]
+# Or merge the extracted data into a new pymrio Extension object (when passing a new name as return_type):
+ext_new = mrio.extension_extract(to_extract, return_type="new_merged_extension")
+str(ext_new)
+
+# %% [markdown]
+# CONT: Extraction to a single extensio does not work.
+# Issue: when only one extension row, it becomes a data series, not a dataframe.
 
-# CONT: DESRIBE STUFF ABOVE
-# For example, to extract the total value added for all regions and sectors we can use:
diff --git a/pymrio/core/mriosystem.py b/pymrio/core/mriosystem.py
index d838c8c5..161655d6 100644
--- a/pymrio/core/mriosystem.py
+++ b/pymrio/core/mriosystem.py
@@ -2428,7 +2428,7 @@ def extension_extract(
         Parameters
         ----------
         index_dict : dict
-            A dict with the index names as keys and the values as the
+            A dict with the extension names as keys and the values as the
             corresponding index values. The values can be a single value or a
             list of values.