How to create links with zarr

zarr-links.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Examples of creating links using Zarr, addressing comments in [GH297](https://github.com/zarr-developers/zarr/issues/297)."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "mkdir: created directory 'data'\r\n"
     ]
    }
   ],
   "source": [
    "import zarr\n",
    "!mkdir -pv data"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "An automated process dumps data every day. They use Zarr and create a new root group for the data from each data. E.g.:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [],
   "source": [
    "# day 1\n",
    "root = zarr.open('data/daily/2018-01-01')\n",
    "# ... save some data.\n",
    "# day 2\n",
    "root = zarr.open('data/daily/2018-01-02')\n",
    "# ... save some data.\n",
    "# day 3\n",
    "root = zarr.open('data/daily/2018-01-03')\n",
    "# ... save some data.\n",
    "# etc."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "\u001b[01;34mdata\u001b[00m\r\n",
      "└── \u001b[01;34mdaily\u001b[00m\r\n",
      "    ├── \u001b[01;34m2018-01-01\u001b[00m\r\n",
      "    │   └── .zgroup\r\n",
      "    ├── \u001b[01;34m2018-01-02\u001b[00m\r\n",
      "    │   └── .zgroup\r\n",
      "    └── \u001b[01;34m2018-01-03\u001b[00m\r\n",
      "        └── .zgroup\r\n",
      "\r\n",
      "4 directories, 3 files\r\n"
     ]
    }
   ],
   "source": [
    "!tree -a data"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# View as single dataset"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "A user now wants to view this as one big dataset, rather than separate datasets."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Option 1 - turn the parent directory into a group\n",
    "\n",
    "In Zarr there is nothing special about a root group. You can turn any directory into a group, and a directory that was initially created as a root group can become a child group. E.g.:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<link rel=\"stylesheet\" href=\"//cdnjs.cloudflare.com/ajax/libs/jstree/3.3.3/themes/default/style.min.css\"/><div id=\"12e8336e-ecfa-45fc-9312-70a392528517\" class=\"zarr-tree\"><ul><li data-jstree='{\"type\": \"Group\"}' class='jstree-open'><span>/</span><ul><li data-jstree='{\"type\": \"Group\"}' class=''><span>2018-01-01</span></li><li data-jstree='{\"type\": \"Group\"}' class=''><span>2018-01-02</span></li><li data-jstree='{\"type\": \"Group\"}' class=''><span>2018-01-03</span></li></ul></li></ul></div>\n",
       "<script>\n",
       "    if (!require.defined('jquery')) {\n",
       "        require.config({\n",
       "            paths: {\n",
       "                jquery: '//cdnjs.cloudflare.com/ajax/libs/jquery/1.12.1/jquery.min'\n",
       "            },\n",
       "        });\n",
       "    }\n",
       "    if (!require.defined('jstree')) {\n",
       "        require.config({\n",
       "            paths: {\n",
       "                jstree: '//cdnjs.cloudflare.com/ajax/libs/jstree/3.3.3/jstree.min'\n",
       "            },\n",
       "        });\n",
       "    }\n",
       "    require(['jstree'], function() {\n",
       "        $('#12e8336e-ecfa-45fc-9312-70a392528517').jstree({\n",
       "            types: {\n",
       "                Group: {\n",
       "                    icon: \"fa fa-folder\"\n",
       "                },\n",
       "                Array: {\n",
       "                    icon: \"fa fa-table\"\n",
       "                }\n",
       "            },\n",
       "            plugins: [\"types\"]\n",
       "        });\n",
       "    });\n",
       "</script>\n"
      ],
      "text/plain": [
       "/\n",
       " ├── 2018-01-01\n",
       " ├── 2018-01-02\n",
       " └── 2018-01-03"
      ]
     },
     "execution_count": 4,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "daily = zarr.open('data/daily')\n",
    "daily.tree()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "<zarr.hierarchy.Group '/2018-01-03'>"
      ]
     },
     "execution_count": 5,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "daily['2018-01-03']"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "\u001b[01;34mdata\u001b[00m\r\n",
      "└── \u001b[01;34mdaily\u001b[00m\r\n",
      "    ├── \u001b[01;34m2018-01-01\u001b[00m\r\n",
      "    │   └── .zgroup\r\n",
      "    ├── \u001b[01;34m2018-01-02\u001b[00m\r\n",
      "    │   └── .zgroup\r\n",
      "    ├── \u001b[01;34m2018-01-03\u001b[00m\r\n",
      "    │   └── .zgroup\r\n",
      "    └── .zgroup\r\n",
      "\r\n",
      "4 directories, 4 files\r\n"
     ]
    }
   ],
   "source": [
    "!tree -a data"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Note that a new '.zgroup' file has been created within the \"daily\" directory."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Option 2 - use file system links\n",
    "\n",
    "This approach is more flexible, as you can create any kind of view you want. E.g.:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "mkdir: created directory 'data/all'\n",
      "'data/daily/2018-01-01' -> 'data/all/2018-01-01'\n",
      "'data/daily/2018-01-01/.zgroup' -> 'data/all/2018-01-01/.zgroup'\n",
      "'data/daily/2018-01-02' -> 'data/all/2018-01-02'\n",
      "'data/daily/2018-01-02/.zgroup' -> 'data/all/2018-01-02/.zgroup'\n",
      "'data/daily/2018-01-03' -> 'data/all/2018-01-03'\n",
      "'data/daily/2018-01-03/.zgroup' -> 'data/all/2018-01-03/.zgroup'\n"
     ]
    }
   ],
   "source": [
    "!mkdir -pv data/all\n",
    "!cp -rv --link data/daily/* data/all"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<link rel=\"stylesheet\" href=\"//cdnjs.cloudflare.com/ajax/libs/jstree/3.3.3/themes/default/style.min.css\"/><div id=\"123d4430-5e8e-48db-b449-b9466a1306d0\" class=\"zarr-tree\"><ul><li data-jstree='{\"type\": \"Group\"}' class='jstree-open'><span>/</span><ul><li data-jstree='{\"type\": \"Group\"}' class=''><span>2018-01-01</span></li><li data-jstree='{\"type\": \"Group\"}' class=''><span>2018-01-02</span></li><li data-jstree='{\"type\": \"Group\"}' class=''><span>2018-01-03</span></li></ul></li></ul></div>\n",
       "<script>\n",
       "    if (!require.defined('jquery')) {\n",
       "        require.config({\n",
       "            paths: {\n",
       "                jquery: '//cdnjs.cloudflare.com/ajax/libs/jquery/1.12.1/jquery.min'\n",
       "            },\n",
       "        });\n",
       "    }\n",
       "    if (!require.defined('jstree')) {\n",
       "        require.config({\n",
       "            paths: {\n",
       "                jstree: '//cdnjs.cloudflare.com/ajax/libs/jstree/3.3.3/jstree.min'\n",
       "            },\n",
       "        });\n",
       "    }\n",
       "    require(['jstree'], function() {\n",
       "        $('#123d4430-5e8e-48db-b449-b9466a1306d0').jstree({\n",
       "            types: {\n",
       "                Group: {\n",
       "                    icon: \"fa fa-folder\"\n",
       "                },\n",
       "                Array: {\n",
       "                    icon: \"fa fa-table\"\n",
       "                }\n",
       "            },\n",
       "            plugins: [\"types\"]\n",
       "        });\n",
       "    });\n",
       "</script>\n"
      ],
      "text/plain": [
       "/\n",
       " ├── 2018-01-01\n",
       " ├── 2018-01-02\n",
       " └── 2018-01-03"
      ]
     },
     "execution_count": 8,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "data = zarr.open('data/all')\n",
    "data.tree()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "\u001b[01;34mdata/all\u001b[00m\r\n",
      "├── \u001b[01;34m2018-01-01\u001b[00m\r\n",
      "│   └── .zgroup\r\n",
      "├── \u001b[01;34m2018-01-02\u001b[00m\r\n",
      "│   └── .zgroup\r\n",
      "├── \u001b[01;34m2018-01-03\u001b[00m\r\n",
      "│   └── .zgroup\r\n",
      "└── .zgroup\r\n",
      "\r\n",
      "3 directories, 4 files\r\n"
     ]
    }
   ],
   "source": [
    "!tree -a data/all"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# View latest day of data\n",
    "\n",
    "Could be done with file system links. E.g.:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "'data/daily/2018-01-01' -> 'data/daily/latest'\r\n",
      "'data/daily/2018-01-01/.zgroup' -> 'data/daily/latest/.zgroup'\r\n"
     ]
    }
   ],
   "source": [
    "!cp -rv --link data/daily/2018-01-01 data/daily/latest"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<link rel=\"stylesheet\" href=\"//cdnjs.cloudflare.com/ajax/libs/jstree/3.3.3/themes/default/style.min.css\"/><div id=\"3ba59d64-f93c-414a-9482-419440ce857f\" class=\"zarr-tree\"><ul><li data-jstree='{\"type\": \"Group\"}' class='jstree-open'><span>/</span><ul><li data-jstree='{\"type\": \"Group\"}' class=''><span>2018-01-01</span></li><li data-jstree='{\"type\": \"Group\"}' class=''><span>2018-01-02</span></li><li data-jstree='{\"type\": \"Group\"}' class=''><span>2018-01-03</span></li><li data-jstree='{\"type\": \"Group\"}' class=''><span>latest</span></li></ul></li></ul></div>\n",
       "<script>\n",
       "    if (!require.defined('jquery')) {\n",
       "        require.config({\n",
       "            paths: {\n",
       "                jquery: '//cdnjs.cloudflare.com/ajax/libs/jquery/1.12.1/jquery.min'\n",
       "            },\n",
       "        });\n",
       "    }\n",
       "    if (!require.defined('jstree')) {\n",
       "        require.config({\n",
       "            paths: {\n",
       "                jstree: '//cdnjs.cloudflare.com/ajax/libs/jstree/3.3.3/jstree.min'\n",
       "            },\n",
       "        });\n",
       "    }\n",
       "    require(['jstree'], function() {\n",
       "        $('#3ba59d64-f93c-414a-9482-419440ce857f').jstree({\n",
       "            types: {\n",
       "                Group: {\n",
       "                    icon: \"fa fa-folder\"\n",
       "                },\n",
       "                Array: {\n",
       "                    icon: \"fa fa-table\"\n",
       "                }\n",
       "            },\n",
       "            plugins: [\"types\"]\n",
       "        });\n",
       "    });\n",
       "</script>\n"
      ],
      "text/plain": [
       "/\n",
       " ├── 2018-01-01\n",
       " ├── 2018-01-02\n",
       " ├── 2018-01-03\n",
       " └── latest"
      ]
     },
     "execution_count": 11,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "daily = zarr.open('data/daily')\n",
    "daily.tree()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "removed 'data/daily/latest/.zgroup'\n",
      "removed directory 'data/daily/latest'\n",
      "'data/daily/2018-01-02' -> 'data/daily/latest'\n",
      "'data/daily/2018-01-02/.zgroup' -> 'data/daily/latest/.zgroup'\n"
     ]
    }
   ],
   "source": [
    "# update latest link\n",
    "!rm -rv data/daily/latest\n",
    "!cp -rv --link data/daily/2018-01-02 data/daily/latest"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# More examples\n",
    "\n",
    "Here's a possible solution to a similar requirement, expressed slightly differently, by @onalant:\n",
    "\n",
    ">Here is my understanding of the problem. Take some zarr store, a.zarr.\n",
    "Every day, some application writes some data to a.zarr. However, it\n",
    "groups the data together by the date on which it was written. We may\n",
    "have have groups like /2018/08/30, for example. What @mrocklin seems\n",
    "to be proposing is having multiple metadata files that \"transmute\" the\n",
    "user-facing appearance of a.zarr. Suppose we also had b.zarr and\n",
    "c.zarr, two stores that refer to a.zarr for data. However, b.zarr\n",
    "specifies in its metadata that it shows the \"latest\" data entries\n",
    "(/2018/08/30, e.g.), while c.zarr \"flattens\" all of the data in\n",
    "a.zarr to appear as though everything were under the root group.\n",
    "\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 13,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "<zarr.hierarchy.Group '/2018/09/01'>"
      ]
     },
     "execution_count": 13,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "a = zarr.open('data/a.zarr')\n",
    "# day 1\n",
    "a.create_group('2018/08/30')\n",
    "# day 2\n",
    "a.create_group('2018/08/31')\n",
    "# day 3\n",
    "a.create_group('2018/09/01')\n",
    "# etc."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 14,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<link rel=\"stylesheet\" href=\"//cdnjs.cloudflare.com/ajax/libs/jstree/3.3.3/themes/default/style.min.css\"/><div id=\"8b291562-d4f0-482e-af3f-a08445395ba7\" class=\"zarr-tree\"><ul><li data-jstree='{\"type\": \"Group\"}' class='jstree-open'><span>/</span><ul><li data-jstree='{\"type\": \"Group\"}' class='jstree-open'><span>2018</span><ul><li data-jstree='{\"type\": \"Group\"}' class='jstree-open'><span>08</span><ul><li data-jstree='{\"type\": \"Group\"}' class='jstree-open'><span>30</span></li><li data-jstree='{\"type\": \"Group\"}' class='jstree-open'><span>31</span></li></ul></li><li data-jstree='{\"type\": \"Group\"}' class='jstree-open'><span>09</span><ul><li data-jstree='{\"type\": \"Group\"}' class='jstree-open'><span>01</span></li></ul></li></ul></li></ul></li></ul></div>\n",
       "<script>\n",
       "    if (!require.defined('jquery')) {\n",
       "        require.config({\n",
       "            paths: {\n",
       "                jquery: '//cdnjs.cloudflare.com/ajax/libs/jquery/1.12.1/jquery.min'\n",
       "            },\n",
       "        });\n",
       "    }\n",
       "    if (!require.defined('jstree')) {\n",
       "        require.config({\n",
       "            paths: {\n",
       "                jstree: '//cdnjs.cloudflare.com/ajax/libs/jstree/3.3.3/jstree.min'\n",
       "            },\n",
       "        });\n",
       "    }\n",
       "    require(['jstree'], function() {\n",
       "        $('#8b291562-d4f0-482e-af3f-a08445395ba7').jstree({\n",
       "            types: {\n",
       "                Group: {\n",
       "                    icon: \"fa fa-folder\"\n",
       "                },\n",
       "                Array: {\n",
       "                    icon: \"fa fa-table\"\n",
       "                }\n",
       "            },\n",
       "            plugins: [\"types\"]\n",
       "        });\n",
       "    });\n",
       "</script>\n"
      ],
      "text/plain": [
       "/\n",
       " └── 2018\n",
       "     ├── 08\n",
       "     │   ├── 30\n",
       "     │   └── 31\n",
       "     └── 09\n",
       "         └── 01"
      ]
     },
     "execution_count": 14,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "a.tree(expand=True)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 15,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "mkdir: created directory 'data/b.zarr'\n",
      "'data/a.zarr/2018/09/01' -> 'data/b.zarr/latest'\n",
      "'data/a.zarr/2018/09/01/.zgroup' -> 'data/b.zarr/latest/.zgroup'\n"
     ]
    }
   ],
   "source": [
    "# create a \"latest\" dataset\n",
    "!mkdir -pv data/b.zarr\n",
    "!cp -rv --link data/a.zarr/2018/09/01 data/b.zarr/latest"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 16,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<link rel=\"stylesheet\" href=\"//cdnjs.cloudflare.com/ajax/libs/jstree/3.3.3/themes/default/style.min.css\"/><div id=\"cb8ff541-f6d3-4f34-bf5f-e5b5e7b444e1\" class=\"zarr-tree\"><ul><li data-jstree='{\"type\": \"Group\"}' class='jstree-open'><span>/</span><ul><li data-jstree='{\"type\": \"Group\"}' class=''><span>latest</span></li></ul></li></ul></div>\n",
       "<script>\n",
       "    if (!require.defined('jquery')) {\n",
       "        require.config({\n",
       "            paths: {\n",
       "                jquery: '//cdnjs.cloudflare.com/ajax/libs/jquery/1.12.1/jquery.min'\n",
       "            },\n",
       "        });\n",
       "    }\n",
       "    if (!require.defined('jstree')) {\n",
       "        require.config({\n",
       "            paths: {\n",
       "                jstree: '//cdnjs.cloudflare.com/ajax/libs/jstree/3.3.3/jstree.min'\n",
       "            },\n",
       "        });\n",
       "    }\n",
       "    require(['jstree'], function() {\n",
       "        $('#cb8ff541-f6d3-4f34-bf5f-e5b5e7b444e1').jstree({\n",
       "            types: {\n",
       "                Group: {\n",
       "                    icon: \"fa fa-folder\"\n",
       "                },\n",
       "                Array: {\n",
       "                    icon: \"fa fa-table\"\n",
       "                }\n",
       "            },\n",
       "            plugins: [\"types\"]\n",
       "        });\n",
       "    });\n",
       "</script>\n"
      ],
      "text/plain": [
       "/\n",
       " └── latest"
      ]
     },
     "execution_count": 16,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "b = zarr.open('data/b.zarr')\n",
    "b.tree()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 17,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "mkdir: created directory 'data/c.zarr'\n",
      "year: 2018\n",
      "month: 08\n",
      "'data/a.zarr/2018/08/30' -> 'data/c.zarr/2018-08-30'\n",
      "'data/a.zarr/2018/08/30/.zgroup' -> 'data/c.zarr/2018-08-30/.zgroup'\n",
      "'data/a.zarr/2018/08/31' -> 'data/c.zarr/2018-08-31'\n",
      "'data/a.zarr/2018/08/31/.zgroup' -> 'data/c.zarr/2018-08-31/.zgroup'\n",
      "month: 09\n",
      "'data/a.zarr/2018/09/01' -> 'data/c.zarr/2018-09-01'\n",
      "'data/a.zarr/2018/09/01/.zgroup' -> 'data/c.zarr/2018-09-01/.zgroup'\n"
     ]
    }
   ],
   "source": [
    "%%bash\n",
    "# create a flattened hierarchy\n",
    "mkdir -pv data/c.zarr\n",
    "for year in $(ls -1 data/a.zarr); do\n",
    "    echo year: $year\n",
    "    for month in $(ls -1 data/a.zarr/${year}); do\n",
    "        echo month: $month\n",
    "        for day in $(ls -1 data/a.zarr/${year}/${month}); do\n",
    "            cp -rv --link data/a.zarr/${year}/${month}/${day} data/c.zarr/${year}-${month}-${day}\n",
    "        done\n",
    "    done\n",
    "done\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 18,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<link rel=\"stylesheet\" href=\"//cdnjs.cloudflare.com/ajax/libs/jstree/3.3.3/themes/default/style.min.css\"/><div id=\"bbff88d5-8c1b-44e3-b83a-dce582f3c9ea\" class=\"zarr-tree\"><ul><li data-jstree='{\"type\": \"Group\"}' class='jstree-open'><span>/</span><ul><li data-jstree='{\"type\": \"Group\"}' class=''><span>2018-08-30</span></li><li data-jstree='{\"type\": \"Group\"}' class=''><span>2018-08-31</span></li><li data-jstree='{\"type\": \"Group\"}' class=''><span>2018-09-01</span></li></ul></li></ul></div>\n",
       "<script>\n",
       "    if (!require.defined('jquery')) {\n",
       "        require.config({\n",
       "            paths: {\n",
       "                jquery: '//cdnjs.cloudflare.com/ajax/libs/jquery/1.12.1/jquery.min'\n",
       "            },\n",
       "        });\n",
       "    }\n",
       "    if (!require.defined('jstree')) {\n",
       "        require.config({\n",
       "            paths: {\n",
       "                jstree: '//cdnjs.cloudflare.com/ajax/libs/jstree/3.3.3/jstree.min'\n",
       "            },\n",
       "        });\n",
       "    }\n",
       "    require(['jstree'], function() {\n",
       "        $('#bbff88d5-8c1b-44e3-b83a-dce582f3c9ea').jstree({\n",
       "            types: {\n",
       "                Group: {\n",
       "                    icon: \"fa fa-folder\"\n",
       "                },\n",
       "                Array: {\n",
       "                    icon: \"fa fa-table\"\n",
       "                }\n",
       "            },\n",
       "            plugins: [\"types\"]\n",
       "        });\n",
       "    });\n",
       "</script>\n"
      ],
      "text/plain": [
       "/\n",
       " ├── 2018-08-30\n",
       " ├── 2018-08-31\n",
       " └── 2018-09-01"
      ]
     },
     "execution_count": 18,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "c = zarr.open('data/c.zarr')\n",
    "c.tree()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
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