Community Data Science Workshops (Fall 2014)/Day 1 lecture

Welcome to the Saturday lecture section of the Community Data Science Workshop! For about 2 hours, we'll work through an introduction to the Python programming language via both a lecture and hand-on exercises.

Resources

 * Python data types cheat sheet
 * Python loops cheat sheet
 * state_capitals.py -- the state capitals example.

Review Friday material

 * math: using python as a calculator
 * addition, subtraction, multiplication, division
 * division shows something different: 8/2 versus 1/2
 * type
 * there are different types of things in python (called objects)
 * variables that "know about the decimal place" (int) and variables that don't (floats)
 * variables
 * assignment of variaibles
 * e.g., math with variables: scale up a recipe, into an assignment
 * you can assign to a variable and it will replace the old value
 * strings
 * things within quotation marks
 * adding strings with "concatination" (smushing things together)
 * e.g.,
 * concatenating strings and integers don't work (e.g., )
 * 1 is different than "1"; name is different than "name"
 * single quotes versus double quotes (python doesn't care)
 * you can also multiply strings! (although it's not clear why you want to weird)
 * booleans
 * comparisons (e.g.,  or  )
 * you can compare strings (case sensative!)
 * also >, <, and !=
 * type shows that the output of True or False is
 * e.g.,
 * e.g., "i" not in "team"
 * if/elif/else (move to external file)
 * if, something that evaluates to a boolean, and then colon
 * e.g.,
 * e.g., adding else example:
 * e.g., tempreature range
 * e.g., adding elif: fix the bug in the previous program if they were the same age
 * indent with spaces (we use 4 spaces!)
 * functions
 * has a parentheses
 * we've already learnd examples of this: exit, help, type

Lists

 * purpose
 * Stores things in order
 * initialization
 * making a list called my list:
 * comma separated elements. in python they can be a mix of any kind of types
 * len review
 * accessing elements
 * indexing from 0 (now you understand all the zeros we've been using
 * adding elements
 * changing elements
 * slicing lists
 * strings are like lists
 * len
 * length of the empty string
 * length of the empty string

loops and more flow control

 * for loops
 * if statements inside for loops
 * nested for</tt> loops
 * range</tt>
 * while</tt> loops
 * infinite loops
 * if</tt> statements inside while</tt> loops
 * break</tt>
 * raw_input</tt>

dictionaries

 * purpose
 * initialization
 * accessing elements
 * adding elements
 * changing elements
 * keys</tt> and values</tt>

modules

 * purpose
 * builtins
 * imports
 * import random</tt>
 * random.randint</tt>
 * random.choice</tt>

walk through state_capitals.py
Where state_capitals.py from http://mako.cc/teaching/2014/cdsw/state_capitals.py is the grand finale and synthesis of lecture material.