保存最后N个元素

from collections import dequedef search(lines, pattern, history=5): previous_lines = deque(maxlen=history) for line in lines: if pattern in line: yield line, previous_lines previous_lines.append(line)if __name__ == '__main__': with open('/Users/gaoshengmao/Desktop/python') as f: for line, prevlines in search(f, 'o', 5): for pline in prevlines: print(pline, end='') print(line, end='') print('-' * 20)

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