Editing DS4UX (Spring 2016)/Day 2 lecture

== Resources ==

* [[Python data types cheat sheet]]
* [[Python loops cheat sheet]]
* [http://mako.cc/teaching/2015/cdsw-spring/state_capitals.py state_capitals.py] -- the state capitals example.
* [http://communitydata.cc/~mako/cdsw-au2015-lecture1-20151010.ogv cdsw-au2015-lecture1-20151010.ogv] -- Professor Mako Hill's lecture video, which covers most of the concepts from today's lecture.

== Lecture outline ==


=== Lists ===

* purpose
** Stores things ''in order''
* initialization
** making a list called my list: <code>my_list = ["a", "b", "c"]</code>
** comma separated elements. in python they can be a mix of any kind of types
** <code>type(my_list)</code>
* <tt>len()</tt> review
* accessing elements
** indexing like my_list[0]
** indexing starts from the front and we ''start counting at 0'' (now you understand all the zeros we've been using)
** we go from the end with negative numbers
** what happens if we try to move outside of the range? ('''error!'')
* adding elements
** using the the <code>my_list.append()</code> function
** the <code>.append()</code> function is a special kind of function that lists know about
* changing elements
** replacing elements like <code>my_list[0] = "foo"</code>
* finding elements in list
** e.g., <code>"z" in my_list</code>
* slicing lists
** the colon inside the [] is the ''slicing syntax''
** e.g., <code>my_list[0:2]</code> is 0th up to, but not including, the 2nd
** e.g., <code>my_list[2:]</code> 
** e.g., <code>my_list[:2]</code>
** e.g., <code>my_list[:]</code>
* strings are like lists
** we can slice lists
** len()
*** <code>len("")</code> length of the empty string
* many other interesting functions for lists
** e.g., <code>min()</code> and <code>max()</code>
** e.g., create a list of names and sort it <code>names.sort()</code>

=== loops and more flow control ===

* <tt>for</tt> loops
** e.g., <code>for name in names: print name</code>
** e.g., <code>for name in names: print 'hello ' + name</code>
** Super powerful because it can do something many many times. Data science is about doing tedious things very quickly. For is the workhorse that makes this possible.
** Look and see name is after we're done looping.
** ''Move to editor.''
* <tt>if</tt> statements inside <tt>for</tt> loops
** e.g., <code>if name[0] in "AEIOU"</code> then print "starts with a vowel"
** show we can test things outside the loop to show how the comparisons are working
** add an else statement to capture words that start with a consonant
** append to a list within a for loop
** create a counter within a for loop (keep track)
** build up a sentence
* nested <tt>for</tt> loops
* <tt>range()</tt>
* <tt>while</tt> loops
* infinite loops
* <tt>if</tt> statements inside <tt>while</tt> loops
* <tt>break</tt>
* <tt>input()</tt>

=== dictionaries ===
* purpose
* initialization
* accessing elements
* adding elements
* changing elements
* <tt>keys()</tt> and <tt>values()</tt>

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

=== walk through state_capitals.py ===

Where state_capitals.py from http://mako.cc/teaching/2015/cdsw-spring/state_capitals.py is the grand finale and synthesis of lecture material.

[[Category:DS4UX (Spring 2016)]]
@@ Line 1: / Line 1: @@
-== Part 1: Review ==
+== Resources ==
-* math: using python as a calculator
-**addition, subtraction, multiplication, division
+* [[Python data types cheat sheet]]
-**division shows something different: <code>8/2</code> versus <code>2*2</code>
+* [[Python loops cheat sheet]]
-* <tt>type()</tt>
+* [http://mako.cc/teaching/2015/cdsw-spring/state_capitals.py state_capitals.py] -- the state capitals example.
-** there are different types of things in python (called objects)
+* [http://communitydata.cc/~mako/cdsw-au2015-lecture1-20151010.ogv cdsw-au2015-lecture1-20151010.ogv] -- Professor Mako Hill's lecture video, which covers most of the concepts from today's lecture.
-** variables that "know about the decimal place" (int) and variables that don't (floats)
-* variables
+== Lecture outline ==
-** 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., <code>print("Hello" + name)</code>
-** concatenating strings and integers don't work (e.g., <code>print(1 + "mako")</code>)
-** 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., <code>1 == 1</code> or <code>1 == 0</code>)
-*** you can compare strings (case sensative!)
-*** also >, <, and !=
-** type() shows that the output of True or False is <code>bool</code>
-** e.g., <code>"i" in "team"</code>
-** e.g., <code>"i" not in "team"</code>
-* <tt>if</tt>/<tt>elif</tt>/<tt>else</tt> ('''move to external file''')
-** if, something that evaluates to a boolean, and then colon
-** e.g., <code>if "mako" in "makoshark"</code>
-** e.g., adding else example: <code>if brother_age > sister_age</code>
-** e.g., temperature range (e.g., if temp<65 is cold; temp>80 is hot; otherwise, just right)
-** 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()
-== Part 2: New programming concepts ==
 === Lists ===
@@ Line 73: / Line 45: @@
 === loops and more flow control ===
-''See also: [[DS4UX_(Spring_2016)/Working_within_loops|working within loops]].''
 * <tt>for</tt> loops
@@ Line 95: / Line 66: @@
 * <tt>break</tt>
 * <tt>input()</tt>
+=== dictionaries ===
+* purpose
+* initialization
+* accessing elements
+* adding elements
+* changing elements
+* <tt>keys()</tt> and <tt>values()</tt>
 === modules ===
 * purpose
 * builtins
+* imports
 * <tt>import random</tt>
 * <tt>random.randint</tt>
 * <tt>random.choice</tt>
-* <tt>random.sample</tt>
-=== walk through favorite_buildings.py ===
+=== walk through state_capitals.py ===
-Where <code>favorite_buildings.py</code> from http://jtmorgan.net/ds4ux/week2/others/favorite_buildings.py is the grand finale and synthesis of lecture material.
+Where state_capitals.py from http://mako.cc/teaching/2015/cdsw-spring/state_capitals.py is the grand finale and synthesis of lecture material.
 [[Category:DS4UX (Spring 2016)]]