union.ipynb

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   "cells": [
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     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import glob\n",
      "import os.path\n",
      "import urllib\n",
      "import zipfile\n",
      "\n",
      "import fiona\n",
      "from shapely.geometry import shape\n",
      "from shapely.ops import unary_union"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 3
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "if not os.path.exists('vectors.zip'):\n",
      "    urllib.urlretrieve(\n",
      "        \"http://ncp-yamato.stanford.edu/~jdouglass/shapely_sample_vectors.zip\",\n",
      "        \"vectors.zip\")\n",
      "    with zipfile.ZipFile('vectors.zip') as archive:\n",
      "        archive.extractall()\n",
      "\n",
      "in_vectors = glob.glob('sample_vectors/*.shp')"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 4
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "geoms = []\n",
      "for filename in in_vectors:\n",
      "    with fiona.open(filename) as src:\n",
      "        geoms.extend([shape(f['geometry']) for f in src])\n",
      "cumulative_union = unary_union(geoms)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 9
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "cumulative_union"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
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       "output_type": "pyout",
       "prompt_number": 10,
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     "prompt_number": 10
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     "outputs": []
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