# -----------------------------------------------------------------
# Write your entire commit message above this line.
# 
# The first line should be a quick description of what you changed.
# Then leave a blank line. 
# Then, taking as many lines as you want, answer the questions 
# corresponding to your checkpoint. 
#
# Checkpoint 1: 
# - Was it difficult to figure out how to rewrite square() using 
#   a for-loop? What strategies did you use to figure it out? 
#
# Checkpoint 2: 
# - Describe something you understand well, or find interesting, about ranges. 
# - Describe something you're still unsure about related to ranges. 
#
# Checkpoint 3: 
# - Docstrings are meant for humans to read; they don't affect how a program runs. 
#   When you write your own programs in the future, do you think you'll write 
#   docstrings? Why or why not?