updated Ch05

Author: rambasnet

Ch05-Iterations.ipynb

@@ -8,6 +8,8 @@
     "life is full of loops; everyday routines such as going to college, cooking food, slicing vegetables, etc.\n",
     "\n",
     "- loops make computer repeatedly execute some block of code\n",
+    "- two types of loops: **for** and **while**\n",
+    "    - some keywords that may appear in loops:\n",
     "    - **for, while, break, continue, in, for ... else, while... else**\n",
     "    \n",
     "### Slice a carrot\n",
@@ -28,12 +30,19 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "## for loop"
+    "## for loop\n",
+    "- works with range of values\n",
+    "- syntax \n",
+    "```python\n",
+    "for val in rangeofValues:\n",
+    "    # loop body\n",
+    "```\n",
+    "- useful when you know exactly how many times the loop should be executed"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 8,
+   "execution_count": 2,
    "metadata": {},
    "outputs": [
     {
@@ -117,6 +126,12 @@
    "metadata": {},
    "source": [
     "## while loop \n",
+    "- while loop is used when we typically not sure how many times the loop should be executed\n",
+    "- syntax:\n",
+    "``` python\n",
+    "while condition:\n",
+    "    # loop body\n",
+    "```\n",
     "- demonstrate countdown as a script\n",
     "- time.sleep(secs)\n",
     "- os.system(‘clear’); os.name -  'posix', 'nt', 'mac', 'os2', 'ce', 'java', 'riscos'\n"