{
 "metadata": {
  "name": ""
 },
 "nbformat": 3,
 "nbformat_minor": 0,
 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "Running Code in the IPython Notebook"
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {
      "slideshow": {
       "slide_type": "-"
      }
     },
     "source": [
      "Based on [this notebook](http://nbviewer.ipython.org/url/github.com/ipython/ipython/raw/master/examples/notebooks/Part%201%20-%20Running%20Code.ipynb) with very minor changes.\n",
      "\n",
      "---------\n",
      "\n",
      "First and foremost, the IPython Notebook is an interactive environment for writing and running Python code."
     ]
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {
      "slideshow": {
       "slide_type": "-"
      }
     },
     "source": [
      "Code cells allow you to enter and run Python code"
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {
      "slideshow": {
       "slide_type": "-"
      }
     },
     "source": [
      "Run a code cell using `Shift-Enter` or pressing the \"Play\" button in the toolbar above:"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "a = 10"
     ],
     "language": "python",
     "metadata": {
      "slideshow": {
       "slide_type": "-"
      }
     },
     "outputs": [],
     "prompt_number": 2
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "print(a)"
     ],
     "language": "python",
     "metadata": {
      "slideshow": {
       "slide_type": "-"
      }
     },
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "10\n"
       ]
      }
     ],
     "prompt_number": 3
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Managing the IPython Kernel"
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Code is run in a separate process called the IPython Kernel.  The Kernel can be interrupted or restarted.  Try running the following cell and then hit the \"Stop\" button in the toolbar above."
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import time\n",
      "time.sleep(10)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "ename": "KeyboardInterrupt",
       "evalue": "",
       "output_type": "pyerr",
       "traceback": [
        "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m\n\u001b[0;31mKeyboardInterrupt\u001b[0m                         Traceback (most recent call last)",
        "\u001b[0;32m<ipython-input-4-d7b436e260d5>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m()\u001b[0m\n\u001b[1;32m      1\u001b[0m \u001b[0;32mimport\u001b[0m \u001b[0mtime\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m----> 2\u001b[0;31m \u001b[0mtime\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0msleep\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;36m10\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
        "\u001b[0;31mKeyboardInterrupt\u001b[0m: "
       ]
      }
     ],
     "prompt_number": 4
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "If the Kernel dies you will be prompted to restart it. Here we call the low-level system libc.time routine with the wrong argument via\n",
      "ctypes to segfault the Python interpreter:"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import sys\n",
      "from ctypes import CDLL\n",
      "# This will crash a Linux or Mac system; equivalent calls can be made on Windows\n",
      "dll = 'dylib' if sys.platform == 'darwin' else 'so.6'\n",
      "libc = CDLL(\"libc.%s\" % dll) \n",
      "libc.time(-1)  # BOOM!!"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": "*"
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "All of the goodness of IPython works"
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Here are two system aliases:"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "pwd"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "metadata": {},
       "output_type": "pyout",
       "prompt_number": 1,
       "text": [
        "u'/Users/fangohr/hgdocs/teaching/python/notebook'"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "ls"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "IPythonNotebookIntroduction.ipynb\r\n",
        "IPythonNotebookIntroduction.py\r\n",
        "Matplotlib.ipynb\r\n",
        "Matplotlib.py\r\n",
        "Testing_12_testing_plus_pytest.ipynb\r\n",
        "Untitled0.ipynb\r\n",
        "animation.mp4\r\n",
        "filename.png\r\n",
        "filename.svg\r\n",
        "inverse-function-through-rootfinding.ipynb\r\n",
        "lab1.aux\r\n",
        "lab1.html\r\n",
        "lab1.idx\r\n",
        "lab1.ipynb\r\n",
        "lab1.log\r\n",
        "lab1.out\r\n",
        "lab1.pdf\r\n",
        "lab1.pdf.orig\r\n",
        "lab1.py\r\n",
        "lab1.tex\r\n",
        "\u001b[1m\u001b[36mlab1_files\u001b[m\u001b[m/\r\n",
        "lab2.ipynb\r\n",
        "lab2.py\r\n",
        "lab2.tmp\r\n",
        "lab3.ipynb\r\n",
        "lab4.ipynb\r\n",
        "lab5.ipynb\r\n",
        "lab6.ipynb\r\n",
        "lab7.ipynb\r\n",
        "lab8.ipynb\r\n",
        "mydata.txt\r\n",
        "same-or-differents-object.ipynb\r\n",
        "speed-map-vs-for-loop.ipynb\r\n",
        "update-web.sh\r\n"
       ]
      }
     ],
     "prompt_number": 2
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Any command line program can be run using `!` with string interpolation from Python variables:"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "message = 'The IPython notebook is great!'\n",
      "# note: the echo command does not run on Windows, it's a unix command.\n",
      "!echo $message"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "The IPython notebook is great!\r\n"
       ]
      }
     ],
     "prompt_number": 3
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Tab completion works:"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import numpy\n",
      "numpy.random."
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "ename": "SyntaxError",
       "evalue": "invalid syntax (<ipython-input-4-28daab75050a>, line 2)",
       "output_type": "pyerr",
       "traceback": [
        "\u001b[0;36m  File \u001b[0;32m\"<ipython-input-4-28daab75050a>\"\u001b[0;36m, line \u001b[0;32m2\u001b[0m\n\u001b[0;31m    numpy.random.\u001b[0m\n\u001b[0m                 ^\u001b[0m\n\u001b[0;31mSyntaxError\u001b[0m\u001b[0;31m:\u001b[0m invalid syntax\n"
       ]
      }
     ],
     "prompt_number": 4
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Tab completion after `(` brings up a tooltip with the docstring:"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "numpy.random.rand("
     ],
     "language": "python",
     "metadata": {},
     "outputs": []
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Adding `?` opens the docstring in the pager below:"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "magic?"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 5
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Exceptions are formatted nicely:"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "x = 1\n",
      "y = 4\n",
      "z = y/(1-x)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "ename": "ZeroDivisionError",
       "evalue": "integer division or modulo by zero",
       "output_type": "pyerr",
       "traceback": [
        "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m\n\u001b[0;31mZeroDivisionError\u001b[0m                         Traceback (most recent call last)",
        "\u001b[0;32m<ipython-input-6-dc39888fd1d2>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m()\u001b[0m\n\u001b[1;32m      1\u001b[0m \u001b[0mx\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0;36m1\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m      2\u001b[0m \u001b[0my\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0;36m4\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m----> 3\u001b[0;31m \u001b[0mz\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0my\u001b[0m\u001b[0;34m/\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;36m1\u001b[0m\u001b[0;34m-\u001b[0m\u001b[0mx\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
        "\u001b[0;31mZeroDivisionError\u001b[0m: integer division or modulo by zero"
       ]
      }
     ],
     "prompt_number": 6
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Working with external code"
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "There are a number of ways of getting external code into code cells."
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "Pasting code with `>>>` prompts works as expected:"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      ">>> the_world_is_flat = 1\n",
      ">>> if the_world_is_flat:\n",
      "...     print(\"Be careful not to fall off!\")"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Be careful not to fall off!\n"
       ]
      }
     ],
     "prompt_number": 7
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "The `%load` magic lets you load code from URLs or local files:"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "%load?"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 8
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "%matplotlib inline"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 9
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "%load http://matplotlib.sourceforge.net/mpl_examples/pylab_examples/integral_demo.py"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 10
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "## Creating a file on the fly\n",
      "\n",
      "Using the ``%%file`` magic, we can directly create a file"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "%%file helloworld.py\n",
      "print(\"Hello World\")"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Writing helloworld.py\n"
       ]
      }
     ],
     "prompt_number": 14
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "and can see the file on the file system:"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "!ls -l helloworld.py"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "-rw-r--r--  1 fangohr  staff  20 20 Sep 13:25 helloworld.py\r\n"
       ]
      }
     ],
     "prompt_number": 15
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "and execute the file using the python interpreter:\n"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "!python helloworld.py"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Hello World\r\n"
       ]
      }
     ],
     "prompt_number": 16
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "## Type markdown for text and latex\n",
      "\n",
      "For example, if $x=\\alpha$ then $x^2 = \\alpha^2$. Furthermore \n",
      "$$ \\int\\limits_a^b f(x) \\mathrm{d} x = \\Gamma.$$"
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "## Further reading\n",
      "\n"
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "https://github.com/ipython/ipython/tree/master/examples/notebooks#a-collection-of-notebooks-for-using-ipython-effectively"
     ]
    }
   ],
   "metadata": {}
  }
 ]
}