Class 14 — Friday February 18

Tabling

In a loop, a loop — Nesting, but not like a bird — Repeating again

---

Zooming

• Link

---

Look both ways

• Back and ahead

---

Shirt of the day

---

Agenda

• Introduce web processing

• Introduce dataset processing

• Introduce nested loops

---

Download now

• Module url.py

• Provides access to web data

• Program going_rowing.py

• Introduces dataset processing

• Program word_of_the_day.py

• Accesses a web file through the use of local module url.py

• Program rc_printing.py

• Introduces nested looping

---

To do list

• Complete current homeworks

• Review artifacts

---

What is data?

• Facts and figures

---

What is information

• Knowledge

---

What is a dataset

• A dataset is a list whose elements are lists. The elements of the sublists are data

• Datasets are sometimes called tables or data sheets

• The elements of a two-dimensional dataset are called rows. The elements of a row are called data values or cells.

• Most of the datasets that we process will come from the web.

• The datasets acquired by programs are often CSV files; that is, the values are separated by commas.

• One of the CSV dataset we will consider is the best selling fictional books of all time

---

Web pages

• We have created a module url.py to provide some helpful web access.

• Our introduction to interacting with the web in CS 1112 is intentionally simple. Industrial-strength web applications require familiarity with other and more powerful URL modules.

• There is an external library requests worth checking if you have further interest.

---

Program word_of_the_day.py

• Displays the word of the day from the CS 1112 web file word-of-the-day.

• Uses local module url.py

???

---

Program going_rowing.py

• Demonstrates looping through a dataset

• Program run

table: [['A', 'B', 'C'], ['D', 'E', 'F'], ['G', 'H', 'I'], ['J', 'K', 'L', 'M']]

the table has 4 rows

row ['A', 'B', 'C'] has 3 columns

row ['D', 'E', 'F'] has 3 columns

row ['G', 'H', 'I'] has 3 columns

row ['J', 'K', 'L', 'M'] has 4 columns

row 0 : ['A', 'B', 'C']

row 1 : ['D', 'E', 'F']

row 2 : ['G', 'H', 'I']

row 3 : ['J', 'K', 'L', 'M']

---

Program rc_printing.py

• Demonstrates printing a table of values (cells) for a user-specicied number of rows and columns.

• The value of cell should be the sum of its row and column indices.

• Some program runs

Number of rows and columns: 3 4

0 1 2 3

1 2 3 4

2 3 4 5

Number of rows and columns: 4 5

0 1 2 3 4

1 2 3 4 5

2 3 4 5 6

3 4 5 6 7

---

 

---

🦆 © 2022 Jim Cohoon

Resources from previous semesters are available.