Merge pull request #322 from raynamharris/patch-2

03-index-slice-subset.md: add key points

Author: wrightaprilm

_episodes/03-index-slice-subset.md

@@ -16,7 +16,10 @@ objectives:
     - "Locate subsets of data using masks."
     - "Describe BOOLEAN objects in Python and manipulate data using BOOLEANs."
 keypoints:
-    - "FIXME"
+    - "In Python, portions of data can be accessed using indices, slices, column headings, and condition-based subsetting."
+    - "Python uses 0-based indexing, in which the first element in a list, tuple or any other data structure has an index of 0."
+    - "Pandas enables common data exploration steps such as data indexing, slicing and conditional subsetting."
+    
 ---
 
 In lesson 01, we read a CSV into a Python pandas DataFrame.  We learned: