drueck

var DNA_NUCLEOTIDES = ['A', 'T', 'C', 'G'];
var ALL_NUCLEOTIDES = DNA_NUCLEOTIDES.concat('U');

function initialCounts() {
  return DNA_NUCLEOTIDES.reduce(function(counts, nucleotide) {
    counts[nucleotide] = 0;
    return counts;
  }, {});
}

lambdaman2

#Moving up/down dir structure
print os.listdir('.') # current level
print os.listdir('..') # one level up
print os.listdir('../..') # two levels up



# more complex example:
# This will walk the file system beginning in the directory the script is run from. It 
# deletes the empty directories at each level