index defensive programming dental formula depth--first search (dfs) destination node deterministic program dict type - adding an element allowable keys deleting an element keys keys method values method dictionary see dict type dijkstraedsger dimensionalityof data disjunct dispersion dissimilarity metric distributions bell curve see distributionsnormal benford' empirical rule for normal gaussian see distributionsnormal memoryless property normal - uniform divide--and--conquer algorithms divide--and--conquer problem solving docstring don' pass line dot notation dr pangloss dynamic programming - dynamic--time--warping earth--movers distance edge of graph efficient programs einsteinalbert elastic limit of springs elif else encapsulation eniac error bars escape character euclid euclidean distance euclidean mean eulerleonhard except block exceptions - built--in assertionerror indexerror nameerror typeerror valueerror built--in class handling - raising try-except unhandled exhaustive enumeration algorithms square root algorithm exponential decay exponential growth expression extend method extending list factorial iterative implementation recursive implementation false negative false positive feature extraction feature vector fibonacci poem fibonacci sequence - dynamic programming implementation recursive implementation file system files - appending close method file handle open function reading write method