{ "metadata": { "name": "branch-loop-sequence" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# \u5206\u652f, \u5faa\u73af\u548c\u5e8f\u5217\n", "\n", "## \u5206\u652f\u548c\u5faa\u73af" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from IPython.display import Image, display\n", "\n", "for i in range(1, 4):\n", " if i == 1:\n", " display(Image(url='http://img3.douban.com/view/photo/thumb/public/p946773286.jpg'))\n", " elif i == 2:\n", " display(Image(url='http://img3.douban.com/view/photo/thumb/public/p946773315.jpg'))\n", " else:\n", " display(Image(url='http://img3.douban.com/view/photo/thumb/public/p946773327.jpg'))" ], "language": "python", "metadata": {}, "outputs": [ { "html": [ "" ], "output_type": "display_data", "text": [ "" ] }, { "html": [ "" ], "output_type": "display_data", "text": [ "" ] }, { "html": [ "" ], "output_type": "display_data", "text": [ "" ] } ], "prompt_number": 1 }, { "cell_type": "code", "collapsed": false, "input": [ "from IPython.display import HTML, display\n", "\n", "imgs = []\n", "for i in [2, 0, 1, 3]:\n", " imgs.append('' % i)\n", "display(HTML(''.join(imgs)))" ], "language": "python", "metadata": {}, "outputs": [ { "html": [ "" ], "output_type": "display_data", "text": [ "" ] } ], "prompt_number": 2 }, { "cell_type": "code", "collapsed": false, "input": [ "def show_number(x):\n", " ds = []\n", " while True:\n", " ds.append(x % 10)\n", " x = x / 10\n", " if x == 0:\n", " break\n", " imgs = []\n", " for i in reversed(ds):\n", " imgs.append('' % i)\n", " display(HTML(''.join(imgs)))\n", " \n", "for i in range(100, 110):\n", " prime = True\n", " for j in range(2, i - 1):\n", " if i % j == 0:\n", " prime = False\n", " break\n", " if not prime:\n", " continue\n", " show_number(i)" ], "language": "python", "metadata": {}, "outputs": [ { "html": [ "" ], "output_type": "display_data", "text": [ "" ] }, { "html": [ "" ], "output_type": "display_data", "text": [ "" ] }, { "html": [ "" ], "output_type": "display_data", "text": [ "" ] }, { "html": [ "" ], "output_type": "display_data", "text": [ "" ] } ], "prompt_number": 3 }, { "cell_type": "markdown", "metadata": {}, "source": [ "## \u8868\u63a8\u5bfc(list comprehension)" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from IPython.display import HTML, display\n", "\n", "img = ''\n", "display(HTML(''.join([img % i for i in range(10)])))" ], "language": "python", "metadata": {}, "outputs": [ { "html": [ "" ], "output_type": "display_data", "text": [ "" ] } ], "prompt_number": 4 }, { "cell_type": "code", "collapsed": false, "input": [ "from IPython.display import HTML, display\n", "\n", "img = ''\n", "display(HTML(''.join([img % i for i in range(10) if i % 2 == 0])))" ], "language": "python", "metadata": {}, "outputs": [ { "html": [ "" ], "output_type": "display_data", "text": [ "" ] } ], "prompt_number": 5 }, { "cell_type": "markdown", "metadata": {}, "source": [ "\u5b57\u5178\u4e5f\u53ef\u4ee5\u63a8\u5bfc(\u5b57\u5178\u63a8\u5bfc, dict comprehension):" ] }, { "cell_type": "code", "collapsed": false, "input": [ "print {a: b for a, b in [(1, 'one'), (2, 'two')]}" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "{1: 'one', 2: 'two'}\n" ] } ], "prompt_number": 6 }, { "cell_type": "markdown", "metadata": {}, "source": [ "## \u751f\u6210\u5668(generator)\n", "\n", "\u751f\u6210\u5668\u4e5f\u662f\u4e00\u79cd\u5e8f\u5217." ] }, { "cell_type": "code", "collapsed": false, "input": [ "print type(1), type(2.0), type('foo')\n", "print type(i for i in range(10))" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " \n", "\n" ] } ], "prompt_number": 7 }, { "cell_type": "code", "collapsed": false, "input": [ "from IPython.display import HTML, display\n", "\n", "img = ''\n", "display(HTML(''.join(img % i for i in range(3))))" ], "language": "python", "metadata": {}, "outputs": [ { "html": [ "" ], "output_type": "display_data", "text": [ "" ] } ], "prompt_number": 8 }, { "cell_type": "markdown", "metadata": {}, "source": [ "\u8fd9\u79cd\u5e8f\u5217\u53ef\u4ee5\u662f\u65e0\u9650\u957f\u7684:" ] }, { "cell_type": "code", "collapsed": false, "input": [ "def natural_number():\n", " i = 0\n", " while True:\n", " yield i\n", " i += 1\n", "\n", "for i, _ in zip(natural_number(), range(10)):\n", " print i" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "0\n", "1\n", "2\n", "3\n", "4\n", "5\n", "6\n", "7\n", "8\n", "9\n" ] } ], "prompt_number": 9 }, { "cell_type": "markdown", "metadata": {}, "source": [ "## zip" ] }, { "cell_type": "code", "collapsed": false, "input": [ "def even_number():\n", " return (i for i in natural_number() if i % 2 == 0)\n", "\n", "print zip(even_number(), range(3))" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "[(0, 0), (2, 1), (4, 2)]\n" ] } ], "prompt_number": 10 }, { "cell_type": "markdown", "metadata": {}, "source": [ "\u6ce8\u610f\u5143\u7ec4\u7684\u62ec\u53f7\u91cc\u5fc5\u9700\u81f3\u5c11\u6709\u4e00\u4e2a\u9017\u53f7. \u5982\u679c\u5c0f\u62ec\u53f7\u91cc\u6ca1\u6709\u9017\u53f7, \u5c31\u4ec5\u4ec5\u8868\u793a\u4e00\u79cd\u4f18\u5148\u7ea7.\n", "\n", "\u4e0e\u751f\u6210\u5668\u4e0d\u540c, \u8868\u63a8\u5bfc\u6ca1\u6709\u5ef6\u8fdf\u8ba1\u7b97\u7684\u6027\u8d28, \u4e0d\u80fd\u751f\u6210\u65e0\u9650\u957f\u5e8f\u5217(\u4f7f\u7528\u83dc\u5355\u91cc\u7684Kernel > Interrupt\u4e2d\u65ad\u7a0b\u5e8f):" ] }, { "cell_type": "code", "collapsed": false, "input": [ "def even_number():\n", " return [i for i in natural_number() if i % 2 == 0]\n", "\n", "print zip(even_number(), range(3))" ], "language": "python", "metadata": {}, "outputs": [] } ], "metadata": {} } ] }