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A Pythonic way to do MapReduce using hadoop
- jcsalterego 16y agoGreat overview, from top to bottom. Just wondering, is it better performance-wise to explicitly check for key membership than to rely on exceptions? Existing: for line in sys.stdin: name, marks = line.rstrip().split('\t') try: if agregatedmarks.get(name): agregatedmarks.get(name).append(marks) else: agregatedmarks[name] = [marks] except ValueError: pass Or for line in sys.stdin: name, marks = line.rstrip().split('\t') if name in aggregatedmarks: aggregatedmarks.append(marks) else: aggregatedmarks[name] = [marks] This is a common idiom I find myself using (append to an existing list or creating a new one in a larger dict).