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问题：想创建一个字典，其本身是另一个字典的子集
解决方案：利用字典推导式（dictionary comprehension）可轻松解决
# example of extracting a subset from a dictionary from pprint import pprint prices = { ‘ACME‘: 45.23, ‘AAPL‘: 612.78, ‘IBM‘: 205.55, ‘HPQ‘: 37.20, ‘FB‘: 10.75 } # Make a dictionary of all prices over 200 p1 = { key:value for key, value in prices.items() if value > 200 } print("All prices over 200") pprint(p1) # Make a dictionary of tech stocks tech_names = { ‘AAPL‘, ‘IBM‘, ‘HPQ‘, ‘MSFT‘ } p2 = { key:value for key,value in prices.items() if key in tech_names } print("All techs") pprint(p2)
>>> ================================ RESTART ================================ >>> All prices over 200 {‘AAPL‘: 612.78, ‘IBM‘: 205.55} All techs {‘AAPL‘: 612.78, ‘HPQ‘: 37.2, ‘IBM‘: 205.55} >>>
字典推导式的方案清晰且运行起来很快。
【python cookbook】【数据结构与算法】16.从字典中提取子集
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原文地址：http://www.cnblogs.com/apple2016/p/5747573.html
