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Socratica: Python

The YouTube channel Socratica has released a set of high-quality, bite-sized videos for learning the Python programming language. Each video is clear and to the point, with a dash of humour every now and then. This is a set of personal notes on that video series.

Contents

• 1 - Hello World in Python
• 2 - Python Strings
• 3 - Numbers in Python 2
• 4 - Numbers in Python 3
• 5 - Arithmetic in Python 2
• 6 - Arithmetic in Python 3
• 7 - Interactive Help
• 8 - Python Booleans
• 9 - Datetime Module (Dates and Times)
• 10 - If, Then, Else in Python
• 11 - Python Functions
• 12 - Sets in Python
• 13 - Python Lists
• 14 - Python Dictionaries
• 15 - Python Tuples
• 16 - Logging in Python
• 17 - Recursion, the Fibonacci Sequence, and Memoization
• 18 - Python Random Number Generator: the Random Module
• 19 - CSV Files in Python
• 20 - A Random Walk & Monte Carlo Simulation
• 21 - List Comprehension
• 22 - Python Classes and Objects
• 23 - Python and Prime Numbers
• 24 - PyDoc: A Celebration of Documentation
• 25 - XML and ElementTree
• 26 - JSON in Python
• 27 - Lambda Expressions and Anonymous Functions
• 28 - Map, Filter, and Reduce Functions
• 29 - Sorting in Python
• 30 - Text Files in Python
• 31 - Unit Tests in Python
• 32 - Exceptions in Python
• 33 - Urllib: GET Requests
• 34 - Special Methods
• 35 - Iterators, Iterables, and Itertools in Python
• 36 - Generators in Python
• 37 - Regular Expressions in Python
• 38 - SQLite in Python
• 39 - Decorators in Python

1 - Hello World in Python

[Video Link]

This lesson teaches how to:

• Check if Python is installed on your computer

For example: In Windows, open up a Command Prompt by going to Apps and typing in cmd. The Command Prompt icon should pop up. Click on it. In the window that appears, type python and hit Enter. If some text that says "Python" with some numbers after it comes up, then it is already installed. If not, then you may have to download it.

[Personal Warning: Sometimes getting Python to work on Windows can be a pain! You might want to try WinPython first instead.]

• How to use the print() command within the Python console

Generally, whatever is inside of the parentheses is displayed.

• How to exit the Python console with the quit() command

Just type it in and hit Enter. The Python console should close after that.

• How to make a file that opens in Python

Type out some code, such as a print() statment, in a plain text document, and then save it with the extension .py

[Personal Note: If you are wondering what text editor she is using in the video, it is Vim. Since there is a learning curve to Vim, you may or may not want use it if you are also trying to learn Python at the same time.]

2 - Python Strings

[Video Link]

This lesson teaches how to:

• How to store a string inside a variable

Similar to how the term is used within mathematics, a variable is a way to represent a whole range of different things. For example, here is a bit of code...

message = "Meet me tonight."

In this case, the variable is message, and everything after the equals sign is what it represents. A string is simply a list of items, be they letters, numbers, or some other symbols. Everything within the quotation marks is considered a string. Therefore, we used the equals sign to make a variable named message that represents a string containing the sentence Meet me tonight.

To view the string within the Python console, print the variable:

print(message)

We should get...

Meet me tonight.

We can also use apostrophes to specify the contents of a string:

message2 = 'The clock strikes at midnight.'

If we want a string that has an apostrophe within it, then we must use quotation marks:

message3 = "I'm looking for someone to share in an adventure."

If we want a string that has quotation marks within it, then we must use apostrophes:

message4 = 'The phrase "Beam me up, Scotty" was never said on Star Trek.'

If we want a string that has a combination of apostrophes and quotation marks, then we must contain it within three apostrophes or three quotation marks:

movie_quote = """One of my favorite lines from The Godfather is: "I'm going to make him an offer he can't refuse." Do you know who said this?"""

If our string is long, then it may take up more than one line. This will be represented by three dots in front of each new line. It might look something like this:

movie_quote = """One of my favorite lines from The Godfather is:
..."I'm going to make him an offer he can't refuse."
...Do you know who said this?"""

3 - Numbers in Python 2