Day 1 - what did we learn?

 - lists [],  dict {}
   tuples(,), strings '"/""", int/float, bool (True/False/None)
 - variables: python doesn't have variables. it has labels.
   x = 1
   y = x # two pointers to the same value
 - doctest
 - flow control: if/elif/else, while, for, def
 - builtins: enumerate, range, zip, 
 - methods: strip, insert, join, append, split, is*, 
   
Questions:

- Why tuples vs list? (immutable: data integrity, tuple
  unpacking, interning, hashable list)
