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      "Object Oriented Programming\n",
      "===========================\n",
      "\n",
      "We've worked a lot with built-in types:\n",
      "\n",
      "* integers\n",
      "* strings\n",
      "* lists\n",
      "* etc.\n",
      "\n",
      "Some things are too complicated to model using just these basic types, so OOP lets us define our own types, with their own behaviors."
     ]
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      "A simple example\n",
      "----------------\n",
      "\n",
      "Suppose we have a list of geographic\n",
      "coordinates. For each data point, we want to\n",
      "store a city name, latitude, and longitude.\n",
      "We could choose to store them as tuples, like\n",
      "this:\n",
      "\n",
      "    [\n",
      "    (\u201dLos Angeles\u201d, 34.05, -118.25),\n",
      "    (\u201dDenver\u201d, 39.73, -104.98),\n",
      "    (\u201dSeattle\u201d, 47.61, -122.33),\n",
      "    ...\n",
      "    ]\n",
      "\n",
      "But, this starts to get less tractable if we want to\n",
      "store more information. What if we want to add\n",
      "elevation, area, average annual temperature,\n",
      "county and state...\n",
      "\n",
      "    (\u201dSeattle\u201d, \u201dKing\u201d, \u201dWA\u201d, 47.61, -122.33, 520, 71 ... )\n",
      "\n",
      "Object oriented programming let's us do something like this instead:\n",
      "\n",
      "    >>> seattle = City(\u201dSeattle\u201d)\n",
      "    >>> seattle.county = \u201dKing\u201d\n",
      "    >>> seattle.state = \u201dWA\u201d\n",
      "    >>> seattle.lat = 47.61\n",
      "    >>>> seattle.lon = -122.33\n",
      "    ...\n",
      "    >>> seattle.print_location()\n",
      "    Seattle is in King County, WA at 47.61 N, 122.33 W.\n"
     ]
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      "Classes and objects\n",
      "-------------------\n",
      "* A class is like a blueprint.\n",
      "* After defining a class, you can make objects that are instances of that class.\n",
      "* ``seattle = City()`` \u2190 ``City`` is a class, ``seattle`` is an object that is an\n",
      "instance of the ``City`` class\n",
      "* Objects have members and methods:\n",
      "    * Members are like variables\n",
      "    * Methods are like functions.\n",
      "\n",
      "Using our example above:\n",
      "\n",
      "    >> seattle.lat = 47.61\n",
      "    >> seattle.lon = -122.33\n",
      "\n",
      "lat and lon are members, like variables\n",
      "\n",
      "    >> seattle.print_location()\n",
      "\n",
      "print_location is a method, like a function"
     ]
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     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "How to make a new class\n",
      "-----------------------\n",
      "\n",
      "We declare classes in much the same way as we declare functions,\n",
      "but with "
     ]
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    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Constructors\n",
      "------------\n",
      "\n",
      "The first method defined should be called ``__init__``.\n",
      "This method is called whenever you make a new object from your class."
     ]
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