Playing with zarr object stores

zarrObjs.ipynb

{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": 19,
   "id": "b771bbb4",
   "metadata": {},
   "outputs": [],
   "source": [
    "import zarr\n",
    "import numcodecs\n",
    "import json"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 20,
   "id": "a41239a8",
   "metadata": {},
   "outputs": [],
   "source": [
    "class Thing:\n",
    "    i=0;\n",
    "    d=0.1;\n",
    "    s=\"a\";\n",
    "    t=None;\n",
    "    \n",
    "    def __init__(self, i, d, s, t):\n",
    "        self.i = i\n",
    "        self.d = d\n",
    "        self.s = s\n",
    "        self.t = t\n",
    "    \n",
    "    def __str__(self):\n",
    "        return f\"{self.i} {self.d} {self.s} ({self.t})\"\n",
    "    \n",
    "    def toJSON(self):\n",
    "        return json.dumps(self, default=lambda o: o.__dict__, \n",
    "            sort_keys=True, indent=4)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 21,
   "id": "56105666",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "3 0.4 d (2 0.3 c (1 0.2 b (0 0.1 a (None))))\n",
      "{\n",
      "    \"d\": 0.4,\n",
      "    \"i\": 3,\n",
      "    \"s\": \"d\",\n",
      "    \"t\": {\n",
      "        \"d\": 0.3,\n",
      "        \"i\": 2,\n",
      "        \"s\": \"c\",\n",
      "        \"t\": {\n",
      "            \"d\": 0.2,\n",
      "            \"i\": 1,\n",
      "            \"s\": \"b\",\n",
      "            \"t\": {\n",
      "                \"d\": 0.1,\n",
      "                \"i\": 0,\n",
      "                \"s\": \"a\",\n",
      "                \"t\": null\n",
      "            }\n",
      "        }\n",
      "    }\n",
      "}\n"
     ]
    }
   ],
   "source": [
    "a=Thing(0,0.1,\"a\",None)\n",
    "b=Thing(1,0.2,\"b\",a)\n",
    "c=Thing(2,0.3,\"c\",b)\n",
    "d=Thing(3,0.4,\"d\",c)\n"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "5c065aa0",
   "metadata": {},
   "source": [
    "Zarr complains that Thing objects above are not JSON serializable, so let's try dictionaries"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 31,
   "id": "62fb567f",
   "metadata": {},
   "outputs": [],
   "source": [
    "def thing( i, d, s, t ):\n",
    "    return { \"i\":i, \"d\": d, \"s\":s, \"t\":t }\n",
    "\n",
    "a = thing( 0, 0.1, \"a\", None )\n",
    "b = thing( 1, 0.2, \"b\", a )\n",
    "c = thing( 2, 0.3, \"c\", b )\n",
    "d = thing( 3, 0.4, \"d\", c )"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 33,
   "id": "8284d5a5",
   "metadata": {},
   "outputs": [],
   "source": [
    "store = zarr.DirectoryStore('thingObj.zarr')\n",
    "z = zarr.empty(4, dtype=object, store=store, object_codec=numcodecs.JSON())\n",
    "z[0] = a\n",
    "z[1] = b\n",
    "z[2] = c\n",
    "z[3] = d"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 36,
   "id": "1ab79b78",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "{'d': 0.4,\n",
       " 'i': 3,\n",
       " 's': 'd',\n",
       " 't': {'d': 0.3,\n",
       "  'i': 2,\n",
       "  's': 'c',\n",
       "  't': {'d': 0.2,\n",
       "   'i': 1,\n",
       "   's': 'b',\n",
       "   't': {'d': 0.1, 'i': 0, 's': 'a', 't': None}}}}"
      ]
     },
     "execution_count": 36,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "zr = zarr.open('thingObj.zarr', mode='r')\n",
    "zr[3]"
   ]
  }
 ],
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