B05. Methods.ipynb

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   "source": [
    "# B05: Methods"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "A 'Method'  is a computer science term and specific to Object Orientated Programming (OOP). Methods are basically functions that are built in to objects/variables. \n",
    "\n",
    "The syntax for these is simple:\n",
    "\n",
    "object.method(parameter, parameter...)\n",
    "\n",
    "Methods can take parameters (or not!) just like a function but note that they are 'coded in' to objects so not all methods are applicable for all types of object. Note that this is a simplification of what methods are. It is not important to understand their intricacies (yet!) only that they are:\n",
    "\n",
    "<b>Something that performs an action on my objects / variables</b>"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Since we're still learning about lists, lets look at some of the methods available to us with lists."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## List Methods"
   ]
  },
  {
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   "execution_count": null,
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   "outputs": [],
   "source": [
    "mylist1 = ['Eggs','Cheese','Bread','Beer','Crisps']"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Adding an item to a list using append()"
   ]
  },
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   "source": [
    "mylist1.append('Fruit')   # Adding an item to the end of a list  \n",
    "mylist1"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Counting the number of times a values appears within a list:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
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   "outputs": [],
   "source": [
    "mylist1.count('Fruit')     # Counting how many times a value appears within a list"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Removing values from a list:"
   ]
  },
  {
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   "execution_count": null,
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   "outputs": [],
   "source": [
    "mylist1.remove('Fruit')   # Removing all occurances of a value from a list \n",
    "mylist1"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Also some methods can take 'keyword arguments'. This is a way of telling Python that you want a method to operate in a certain way or perform a certain action:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
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   "outputs": [],
   "source": [
    "mylist2 = [3,2,6,5,3,2,4,1,2,0,6]\n",
    "mylist2.sort(reverse=True)     # Sorting a list in reverse order\n",
    "mylist2"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Not all methods need an argument or parameter:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "mylist1.reverse()      # Reverses the order of values in the list \n",
    "mylist1"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Note that Jupyter has some awesome built in functionality to help with methods. If you type your object name followed by a . and then press the tab key it will bring up an exhaustive list of methods applicable to that object type. This is a great way to explore the methods you have available!"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "mylist1."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "The help function can be used with methods too:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "help(mylist1.sort)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Lastly, for more detailed help, you can call the help() function:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "help()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "collapsed": true
   },
   "source": [
    "## Variable Methods"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Methods can also be called on variables too. Note that the method list will differ depending upon the type of variable"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
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   "outputs": [],
   "source": [
    "a = 'Variable'       # String variable"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Some string Variable methods are as follows:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "a.count('a')         # Counts the number of times the supplied argument appears in the variable"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "a.lower()            # Converts the string to lower case"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "a.upper()            # Converts the string to upper case"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "a.capitalize()       # Converts the string to title case"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "a.find('c')          # Finds and returns the index of the first occurance of the argument. Returns -1 if not found."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "a.index('c')         # Returns the index of the argument. Returns an error if not found"
   ]
  }
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