minor changes

Author: nikhilkumarsingh

6. Data structures.ipynb renamed to 5. Data structures.ipynb

@@ -247,10 +247,11 @@
     "\n",
     "![](images/immutable.jpg)\n",
     "\n",
-    "- Tuples are faster than lists. If you're defining a constant set of values and all you're ever going to do with it is iterate through it, use a tuple instead of a list.\n",
+    "- **Storage:** In CPython, tuples are stored in a single block of memory, so creating a new tuple involves at worst a single call to allocate memory. Lists are allocated in two blocks: the fixed one with all the Python object information and a variable sized block for the data. \n",
     "\n",
+    "- **Indexing:** Tuples are faster than lists. Tuples directly reference their elements where as lists have an extra layer of indirection to an external array of pointers.\n",
     "\n",
-    "- It makes your code safer if you “write-protect” data that does not need to be changed. Using a tuple instead of a list is like having an implied assert statement that this data is constant, and that special thought (and a specific function) is required to override that."
+    "- **Safety:** It makes your code safer if you “write-protect” data that does not need to be changed. Using a tuple instead of a list is like having an implied assert statement that this data is constant, and that special thought (and a specific function) is required to override that.\n"
    ]
   },
   {
@@ -392,6 +393,13 @@
    "outputs": [],
    "source": []
   },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "args, kwargs and call by object"
+   ]
+  },
   {
    "cell_type": "markdown",
    "metadata": {},

5. Modules.ipynb renamed to 6. Modules.ipynb

@@ -2,20 +2,14 @@
  "cells": [
   {
    "cell_type": "markdown",
-   "metadata": {
-    "deletable": true,
-    "editable": true
-   },
+   "metadata": {},
    "source": [
     "# Modules"
    ]
   },
   {
    "cell_type": "markdown",
-   "metadata": {
-    "deletable": true,
-    "editable": true
-   },
+   "metadata": {},
    "source": [
     "You have seen how you can reuse code in your program by defining functions once. What if you wanted to reuse a number of functions in other programs that you write? As you might have guessed, the answer is modules.\n",
     "\n",
@@ -28,9 +22,7 @@
    "cell_type": "code",
    "execution_count": null,
    "metadata": {
-    "collapsed": true,
-    "deletable": true,
-    "editable": true
+    "collapsed": true
    },
    "outputs": [],
    "source": [
@@ -39,10 +31,7 @@
   },
   {
    "cell_type": "markdown",
-   "metadata": {
-    "deletable": true,
-    "editable": true
-   },
+   "metadata": {},
    "source": [
     "### Challenge\n",
     "Write a python program which takes input from command line and outputs sum of two itegers."
@@ -52,19 +41,14 @@
    "cell_type": "code",
    "execution_count": null,
    "metadata": {
-    "collapsed": true,
-    "deletable": true,
-    "editable": true
+    "collapsed": true
    },
    "outputs": [],
    "source": []
   },
   {
    "cell_type": "markdown",
-   "metadata": {
-    "deletable": true,
-    "editable": true
-   },
+   "metadata": {},
    "source": [
     "## The from..import statement "
    ]
@@ -80,40 +64,29 @@
    "cell_type": "code",
    "execution_count": null,
    "metadata": {
-    "collapsed": true,
-    "deletable": true,
-    "editable": true
+    "collapsed": true
    },
    "outputs": [],
    "source": []
   },
   {
    "cell_type": "markdown",
-   "metadata": {
-    "deletable": true,
-    "editable": true
-   },
+   "metadata": {},
    "source": [
     "### Challenges:\n",
     "[Polar Coordinates](https://www.hackerrank.com/challenges/polar-coordinates)"
    ]
   },
   {
    "cell_type": "markdown",
-   "metadata": {
-    "deletable": true,
-    "editable": true
-   },
+   "metadata": {},
    "source": [
     "## Making Your Own Modules"
    ]
   },
   {
    "cell_type": "markdown",
-   "metadata": {
-    "deletable": true,
-    "editable": true
-   },
+   "metadata": {},
    "source": [
     "## Problem with importing my modules\n",
     "\n",
@@ -144,7 +117,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.5.2+"
+   "version": "3.6.3"
   }
  },
  "nbformat": 4,