From aa25f2831792794649f2c80176aa609850c2a413 Mon Sep 17 00:00:00 2001
From: Louis Oliphant <ltoliphant@wisc.edu>
Date: Sat, 5 Oct 2024 08:57:24 -0500
Subject: [PATCH] working on lec 14
---
.../14_Lists/Lec_14_Lists.ipynb | 68 ++++++++++++++++---
1 file changed, 58 insertions(+), 10 deletions(-)
diff --git a/f24/Louis_Lecture_Notes/14_Lists/Lec_14_Lists.ipynb b/f24/Louis_Lecture_Notes/14_Lists/Lec_14_Lists.ipynb
index 2854404..72af2de 100644
--- a/f24/Louis_Lecture_Notes/14_Lists/Lec_14_Lists.ipynb
+++ b/f24/Louis_Lecture_Notes/14_Lists/Lec_14_Lists.ipynb
@@ -8,8 +8,10 @@
]
},
{
- "cell_type": "markdown",
+ "cell_type": "code",
+ "execution_count": null,
"metadata": {},
+ "outputs": [],
"source": [
"# Warmup 0: Complete the 5 TODOs!\n",
"def get_wordle_results(guess):\n",
@@ -127,9 +129,9 @@
"- Create a list and use sequence operations on a list.\n",
"- Write loops that process lists\n",
"- Explain key differences between strings and lists: type flexibility, mutability\n",
- "- Mutate a list using \n",
- " - indexing and double indexing, \n",
- " - methods such as append, extend, sort, and pop\n",
+ "- Mutate a list using\n",
+ " - indexing and double indexing, \n",
+ " - methods such as append, extend, sort, and pop\n",
"- split() a string into a list\n",
"- join() list elements into a string"
]
@@ -138,14 +140,45 @@
"cell_type": "markdown",
"metadata": {},
"source": [
- "### Create a list and use sequence operations on a list."
+ "### Creating Lists\n",
+ "\n",
+ "A **list** is used to store multiple items into a single data structure. To create a list you use square brackets `[]`.\n",
+ "\n",
+ "**Be Careful** -- notice that square brackets now have two meanings in Python. They are used for indexing and slicing (i.e. accessing the items within a sequence) and they are use for creating. Let's see the difference:\n",
+ "\n",
+ "**Indexing and Slicing:**\n",
+ "\n",
+ "```python\n",
+ "name = 'rumplestiltskin'\n",
+ "last_part = name[-4:] # <----slicing the value 'skin'\n",
+ "first_ch = name[0] # <----indexing the value 'r'\n",
+ "```\n",
+ "\n",
+ "**Creating a List:**\n",
+ "\n",
+ "```python\n",
+ "nothing = [] # <-- creating an empty list\n",
+ "greetings = ['hello','hola','dag','Kon\\'nichiwa'] # <-- creating a list of 4 strings\n",
+ "primes = [23,27,29] # <-- creating a list of 3 integers\n",
+ "rand_items = ['flugelhorn',23.17, True, 973] # <-- creating a list of 4 items (mixed types)\n",
+ "```\n",
+ "\n",
+ "Do you see the difference? If the square brackets *come right after a sequence* then you are accessing an item or items in the sequence. If the square brackets *stand alone* then you are creating a list."
]
},
{
"cell_type": "code",
- "execution_count": null,
+ "execution_count": 1,
"metadata": {},
- "outputs": [],
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "['bread', 'milk', 'eggs', 'apples', 'macNcheese']\t5\n"
+ ]
+ }
+ ],
"source": [
"# A list is a sequence seperated by commas\n",
"\n",
@@ -154,6 +187,17 @@
"print(grocery_list, len(grocery_list), sep='\\t')"
]
},
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "A list is a sequence so you can use all of the sequencing techniques you used with strings when you are working with lists. Namely, you can use the `len()` function, indexing, slicing, and `for` loops to work with the items in a list.\n",
+ "\n",
+ "### You Try It\n",
+ "\n",
+ "Change the code in the cell below to access the elements of the `grocery_list`."
+ ]
+ },
{
"cell_type": "code",
"execution_count": null,
@@ -170,8 +214,12 @@
"# TODO: print the last item in grocery_list\n",
"print(grocery_list) \n",
"\n",
- "# TODO: slice the list!\n",
- "print(grocery_list) \n"
+ "# TODO: slice to get the eggs and apples\n",
+ "print(grocery_list) \n",
+ "\n",
+ "## TODO: finish the for loop to print out every item in the list\n",
+ "for ??? in ???:\n",
+ " pass\n"
]
},
{
@@ -624,7 +672,7 @@
"name": "python",
"nbconvert_exporter": "python",
"pygments_lexer": "ipython3",
- "version": "3.10.6"
+ "version": "3.10.12"
}
},
"nbformat": 4,
--
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