Python for Everybody (py4e.com)

Explore the nature of programming and how programming a computer is different than using a computer.

In this lecture we learn abut how the computer processes and stores programs. We learn about the CPU, Memory, Storage and Input / Output devices are brought together to write a program.

We look at how writing programs is just another form of communication. Instead of communicating with another person, we are communicating our ideas to a computer.

We look at the basics of the Python language and how we write code in Python to communicate sequential steps, conditional steps and repeated steps.

Installing Python 3 on a Macintosh

Code Walkthrough: Hello World

We look at Python's reserved words, how we name and use variables, why we choose meaningful (mnemonic) variable names and how assignment statements function.

We look at how we use various numerical and string operations to compute new information and store the new values in variables.

Code Walkthrough: Exercise 2.2

Code Walkthrough: Exercise 2.3

The most basic conditional structure is the if statement where we either execute or skip a segment of code based on the results of a logical expression (i.e. asking a question).

In this video we look at multi-branch if statements and the try-except concept where we can indicate a group of statements to be executed if something goes wrong with a block of statements.

Code Walkthrough: Exercise 3.1

Code Walkthrough: Exercise 3.2

We look at how code flows into and out of functions as well has how we pass information into functions and get results returned to us.

We look at how to build our own functions using parameters and arguments as well as how we return results to the code that is calling our functions.

Code Walkthrough: Exercise 4.6

We look at how we construct a loop so that it runs as long as we want it to run. We learn about iteration variables and exiting loops with the 'break' and 'continue' statements.

We learn how to use the 'for' statement in Python to loop through a set of data.

Loops have a beginning, middle, and end. We look ant how we construct a loop to look at a list of items one at a time so we can compute an overall maximum, minimum or average.

We continue to look at how to construct loops including how to do something special the first time through the loop. We introduce the idea of 'None' which is a way to indicate that a variable is currently empty.

Worked Exercise: Exercise 5.1

We learn how to create string variables and extract portions of the data as well as write simple loops to read through the characters in a string.

We learn how to extract substrings using slicing, and use the string library to perform common data extraction operations with strings.

Worked Example: Exercise 6.5

We look at how text and lines are represented in files, how we open a file and write a loop to read through all the lines in the file.

We look at patterns for reading and processing the data in files. We learn how to check for nonexistent files, and how we process each line within the file.

Worked Example: Exercise 7.1

We learn how to put data into lists, take data out of the list and write simple loops to examine the elements of a list.

We learn about list slicing, list searching, and using pre-defined functions with lists.

We learn how to parse strings pull sub-strings out of a string using the split() function.

Strings, Files, Lists and the Guardian Pattern.

We compare and contrast how Python lists and dictionaries are structured internally. How we use position to index lists and use keys to index dictionaries.

We look at how we can use dictionaries to count the frequencies of many things at the same time. We learn how the key and value are related in a dictionary and example the get method to retrieve values from a Python dictionary.

In this segment we bring everything together, reading a file, parsing the lines, and computing the frequencies of the words in the file. This is an important moment that pulls from everything we have learned so far.

Worked Exercise: Dictionaries

We look at the basic syntax and capabilities of Python tuples. We explore the concept of immutability, and we compare tuples to lists and strings.

We look at how we sort lists, dictionaries, and lists of tuples in Python.

Worked Example: Sorting Dictionaries

We look at the syntax of regular expressions and how to use them to search through text data.

In this segment we learn to pull out data from strings after a regular expression has found a match.

We look at how some of the string parsing we have done in earlier chapters can be easily done with regular expressions.

We take a very brief look at how software communicates across the Internet using TCP/IP.

In this section we look at the HTTP protocol that is used to move documents between web servers and web browsers.

We write a simple Python program that connects to a web server and retrieves a web document. It is a very simple web browser.

Worked Example: Sockets

We explore how characters are encoded when they are transported across the network.

We write an even simpler Python program to retrieve a web page using the urllib library in Python.

Worked Example: Using urllib

Now we will look at the HypertextMarkup Language (HTML) that we retrieved using Python and extract links from that HTML. We are slowly building a very simple web search engine.