python学习——内置函数练习
用map来处理字符串列表,把列表中所有人都变成sb,比方alex_sb
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1 name=['oldboy','alex','wusir'] 2 print(list(map(lambda x:x+'_sb',name)))
用map来处理下述l,然后用list得到一个新的列表,列表中每个人的名字都是sb结尾
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1 l=[{'name':'alex'},{'name':'y'}] 2 print(list(map(lambda x:x['name']+'sb',l)))
用filter来处理,得到股票价格大于20的股票名字
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1 shares={ 2 'IBM':36.6, 3 'Lenovo':23.2, 4 'oldboy':21.2, 5 'ocean':10.2, 6 } 7 print(list(filter(lambda x:shares[x]>20,shares)))
有下面字典,得到购买每只股票的总价格,并放在一个迭代器中。结果:lis=[9110.0, 27161.0,......]
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1 portfolio = [ 2 {'name': 'IBM', 'shares': 100, 'price': 91.1}, 3 {'name': 'AAPL', 'shares': 50, 'price': 543.22}, 4 {'name': 'FB', 'shares': 200, 'price': 21.09}, 5 {'name': 'HPQ', 'shares': 35, 'price': 31.75}, 6 {'name': 'YHOO', 'shares': 45, 'price': 16.35}, 7 {'name': 'ACME', 'shares': 75, 'price': 115.65}] 8 print(list(map(lambda x:x['shares']*x['price'],portfolio)))
还是上面的字典,用filter过滤出单价大于100的股票
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1 print(list(filter(lambda x:x['price']>100,portfolio)))
有下列三种数据类型,写代码,最终得到的是(每个元祖第一个元素>2,第三个*至少是4个)[(3, 'wusir', '****'), (4, '太白', '*******')]这样的数据。
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1 l1 = [1,2,3,4,5,6] 2 l2 = ['oldboy','alex','wusir','太白','日天'] 3 tu = ('**','***','****','*******') 4 print(list(filter(lambda x:x[0]>2 and len(x[2])>3,zip(l1,l2,tu))))
有如下数据类型:将lst1按照列表中的每个字典的values大小进行排序,形成一个新的列表。
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1 lst1 = [ {'sales_volumn': 0}, 2 {'sales_volumn': 108}, 3 {'sales_volumn': 337}, 4 {'sales_volumn': 475}, 5 {'sales_volumn': 396}, 6 {'sales_volumn': 172}, 7 {'sales_volumn': 9}, 8 {'sales_volumn': 58}, 9 {'sales_volumn': 272}, 10 {'sales_volumn': 456}, 11 {'sales_volumn': 440}, 12 {'sales_volumn': 239}] 13 print(sorted(lst1,key=lambda x:x['sales_volumn']))