40 lines
991 B
Python
40 lines
991 B
Python
#!/usr/bin/env python
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# -*- encoding: utf-8 -*-
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"""
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Topic: 转换并聚集函数
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Desc :
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"""
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import os
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def trans_reduce():
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nums = [1, 2, 3, 4, 5]
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s = sum(x * x for x in nums)
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print(s)
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files = os.listdir('dirname')
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if any(name.endswith('.py') for name in files):
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print('There be python!')
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else:
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print('Sorry, no python.')
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# Output a tuple as CSV
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s = ('ACME', 50, 123.45)
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print(','.join(str(x) for x in s))
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# Data reduction across fields of a data structure
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portfolio = [
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{'name':'GOOG', 'shares': 50},
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{'name':'YHOO', 'shares': 75},
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{'name':'AOL', 'shares': 20},
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{'name':'SCOX', 'shares': 65}
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]
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min_shares = min(s['shares'] for s in portfolio)
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# Original: Returns 20
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min_shares = min(s['shares'] for s in portfolio)
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# Alternative: Returns {'name': 'AOL', 'shares': 20}
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min_shares = min(portfolio, key=lambda s: s['shares'])
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if __name__ == '__main__':
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trans_reduce()
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