Audio processing in Python.ipynb

Python Basics.ipynb

{
 "metadata": {
  "name": "Python Basics"
 },
 "nbformat": 3,
 "nbformat_minor": 0,
 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "# Introduction to Python\n",
      "\n",
      "Why Python?\n",
      "\n",
      "- Python is free\n",
      "- Python is Open Source\n",
      "- Python is more powerful than Matlab"
     ]
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "## Typing\n",
      "\n",
      "Like Matlab, Python is *dynamically typed*.   \n",
      "Unlinke Matlab, Python is *strongly typed*.\n",
      "\n",
      "### Dynamic Typing\n",
      "\n",
      "(Like Matlab, unlike C)"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# Python:\n",
      "a = 5.0\n",
      "a = 'text'\n",
      "a = [1, 2, 3]"
     ],
     "language": "python",
     "metadata": {},
     "outputs": []
    },
    {
     "cell_type": "code",
     "collapsed": true,
     "input": [
      "# C:\n",
      "float a = 5.0;\n",
      "char b[] = \"text\";\n",
      "int c[3] = {1, 2, 3};"
     ],
     "language": "python",
     "metadata": {},
     "outputs": []
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "### Strongly Typed\n",
      "\n",
      "(unlike Matlab or C)"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# Matlab:\n",
      "a = 'text';\n",
      "b = a + 5;"
     ],
     "language": "python",
     "metadata": {},
     "outputs": []
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# Python:\n",
      "a = 'text'\n",
      "b = a + 5"
     ],
     "language": "python",
     "metadata": {},
     "outputs": []
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "## Syntax\n",
      "\n",
      "Many small differences to Matlab\n",
      "\n",
      "### No Semikolons\n",
      "\n",
      "$\\Rightarrow$  use `print()`-function instead"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# does not print:\n",
      "a = 5\n",
      "# instead:\n",
      "print(a)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": []
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "### Branches, Loops\n",
      "\n",
      "*Whitespace is important!*"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# Python:\n",
      "if a == 5:\n",
      "    print('A is five')\n",
      "elif a == 6:\n",
      "    print('A is six')\n",
      "else:\n",
      "    print('A is neither five nor six')"
     ],
     "language": "python",
     "metadata": {},
     "outputs": []
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# Matlab:\n",
      "if a == 5\n",
      "    disp('A is five')\n",
      "elseif a == 6\n",
      "    disp('A is six')\n",
      "else\n",
      "    disp('A is neither five nor six')\n",
      "end"
     ],
     "language": "python",
     "metadata": {},
     "outputs": []
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "*Write for-loops with `in` instead of `=`*"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# Python:\n",
      "for n in [1, 2, 3, 4, 5, 6]: # These commas are important!\n",
      "    print(n)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "1\n",
        "2\n",
        "3\n",
        "4\n",
        "5\n",
        "6\n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# Matlab:\n",
      "for n = [1 2 3 4 5 6]\n",
      "    disp(n)\n",
      "end"
     ],
     "language": "python",
     "metadata": {},
     "outputs": []
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "*While-Loop:*"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# Fibonacci Series: 1 1 2 3 5 8 13...\n",
      "a = 1\n",
      "b = 1\n",
      "while b < 100:\n",
      "    print(b)\n",
      "    tmp = b\n",
      "    b = a + b\n",
      "    a = tmp"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "1\n",
        "2\n",
        "3\n",
        "5\n",
        "8\n",
        "13\n",
        "21\n",
        "34\n",
        "55\n",
        "89\n"
       ]
      }
     ],
     "prompt_number": 2
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "*Multiple Assignment:*"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# shorter:\n",
      "a = 1\n",
      "b = 1\n",
      "while b < 100:\n",
      "    print(b)\n",
      "    a, b = b, a + b"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "1\n",
        "2\n",
        "3\n",
        "5\n",
        "8\n",
        "13\n",
        "21\n",
        "34\n",
        "55\n",
        "89\n"
       ]
      }
     ],
     "prompt_number": 3
    },
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "## Types"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# float\n",
      "a = 5.0\n",
      "print(type(a))"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "<class 'float'>\n"
       ]
      }
     ],
     "prompt_number": 4
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# integer\n",
      "a = 4\n",
      "print(type(a))"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "<class 'int'>\n"
       ]
      }
     ],
     "prompt_number": 5
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# bool\n",
      "a = True # or False\n",
      "print(type(a))"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "<class 'bool'>\n"
       ]
      }
     ],
     "prompt_number": 6
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# string\n",
      "a = 'text'\n",
      "print(type(a))"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "<class 'str'>\n"
       ]
      }
     ],
     "prompt_number": 7
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# list\n",
      "a = [1, 'text', True]\n",
      "print(type(a))\n",
      "print(a[0], a[1], a[2]) # counting from 0!"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "<class 'list'>\n",
        "1 text True\n"
       ]
      }
     ],
     "prompt_number": 8
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# tuple\n",
      "a = (1, 'text', True)\n",
      "print(type(a))\n",
      "print(a[0], a[1], a[2]) # counting from 0!"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "<class 'tuple'>\n",
        "1 text True\n"
       ]
      }
     ],
     "prompt_number": 9
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# dictionary\n",
      "a = {'first':   1,\n",
      "     'second': 'text',\n",
      "     'third':   True}\n",
      "print(type(a))\n",
      "print(a['first'], a['second'], a['third'])"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "<class 'dict'>\n",
        "1 text True\n"
       ]
      }
     ],
     "prompt_number": 10
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# function (can be defined anywhere, not just in special files)\n",
      "def func(a):\n",
      "    print('a ist ' + str(a))\n",
      "\n",
      "print(type(func))\n",
      "func(a)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "<class 'function'>\n",
        "a ist {'second': 'text', 'third': True, 'first': 1}\n"
       ]
      }
     ],
     "prompt_number": 11
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# class (can be defined anywhere, not just in special files)\n",
      "class MyClass:\n",
      "    def __init__(self, num):\n",
      "        self.number = num\n",
      "    def func(self, num):\n",
      "        print(self.number + num)\n",
      "\n",
      "print(type(MyClass))\n",
      "c = MyClass(5)\n",
      "c.func(6)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "<class 'type'>\n",
        "11\n"
       ]
      }
     ],
     "prompt_number": 12
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [],
     "language": "python",
     "metadata": {},
     "outputs": []
    }
   ],
   "metadata": {}
  }
 ]
}

Python instead of Matlab.ipynb