A simple tutorial using a Jupyter notebook

Using Python Packages.ipynb

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   "cell_type": "markdown",
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   "source": [
    "# Using Python packages\n",
    "## A super-simple how-to, illustrated with a Jupyter notebook\n",
    "\n",
    "In order to make use of a Python package we have installed, we must first \"import\" it."
   ]
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      "2.7.15 (default, Jul 23 2018, 21:27:06) \n",
      "[GCC 4.2.1 Compatible Apple LLVM 9.1.0 (clang-902.0.39.2)]\n"
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   "source": [
    "import sys\n",
    "print sys.version"
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   "source": [
    "If we don't import it, it simply doesn't exist, and we'll get a NameError trying to reference it."
   ]
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  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [
    {
     "ename": "NameError",
     "evalue": "name 'numpy' is not defined",
     "output_type": "error",
     "traceback": [
      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
      "\u001b[0;31mNameError\u001b[0m                                 Traceback (most recent call last)",
      "\u001b[0;32m<ipython-input-2-aa642aae9327>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m()\u001b[0m\n\u001b[0;32m----> 1\u001b[0;31m \u001b[0mfoo\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0mnumpy\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0marray\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m[\u001b[0m\u001b[0;36m1\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0;36m2\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0;36m3\u001b[0m\u001b[0;34m]\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
      "\u001b[0;31mNameError\u001b[0m: name 'numpy' is not defined"
     ]
    }
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   "source": [
    "foo = numpy.array([1, 2, 3])"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "But if we import numpy first, everything works just dandy."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[1 2 3]\n"
     ]
    }
   ],
   "source": [
    "import numpy\n",
    "foo = numpy.array([1, 2, 3])\n",
    "print foo"
   ]
  }
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