Python Crash Course Notes Link to heading

Content Link to heading

• Python Crash Course Notes
• Content
  • Basics
    • Variable types
    • Some more tips
    • Control flow structures
    • Functions and arguments
    • Classes and objects
    • Files and Exceptions
  • Project: Alien Invasion
  • Project: Data visualization
  • Project: Web applications

Basics Link to heading

Variable types Link to heading

• Strings str
• Integers int
  • Long numbers can be written with underscores _ for readability. 14_000_000_000
• Floats float
  • Dividing ints will result in a float number
• Lists list
  • Collection of items (ints, strs, floats, lists, etc)
  • .pop(), del x[x], .remove() remove items from a list, pop returns the value
• Tuples: tuple
  • Immutable list of items (strings, ints, floats, tuples, lists, etc)
• Dictionaries dict
  • Collection of key-value pairs items (strs, ints, floats, lists, tuples, dicts, etc)

Some more tips Link to heading

• Looking for documentation? No worries you can always run python -m pydoc -b and it will load your current environment packages and all its documentation in http://localhost:58261
• If you want to know more about a particular object you can always check it with help() or dir() functions. For example help(list) or dir(list).
  • You can also read a brief description of whatever you have in ipython typing ? or ?? after any variable or function. For example list? or list??.
• You can also check what are the current built-ins available for you with: help(__builtins__) or dir(__builtins__).
  • Common builtin functions: input, range, type, random module, open,

Control flow structures Link to heading

Those are: if, elif, else, for, while, break, continue, pass, with. - To break the while loop, you can use a flag variable or the break statement.

Functions and arguments Link to heading

Classes and objects Link to heading

• __init__() special method that runs on each obj instantiation
• self parameter is a reference of the instance itself, always goes first in the method definition
• Inheritance: class ChildClass(ParentClass):...
  • The init function has to invoke the parent’s class init function: super().__init__(foo, bar, baz)
  • A class parameter can also be another object which has parameters and functions

Files and Exceptions Link to heading

• We can write to files, also read, append, etc. 🦆

Exceptions

• TODO: What kind of Exceptions we should care?: FilenoError, FileNotFoundError, ZeroDivisionError, etc
• try, except, else, finally blocks
  • You can check all available exceptions by: import builtins then [exc for exc in dir(builtins) if 'Error' in exc or 'Exception' in exc]
  • Then check the exception class: help(FileNotFoundError)

Testing your code Link to heading

• Usage of unittest module


Project: Alien Invasion Link to heading

Project: Data visualization Link to heading

Project: Web applications Link to heading