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在python中用元组值计算两个字典的点积

Jerry M. • 4 年前 • 1034 次点击  

我有两本这样的字典:

dict_of_items = tf_idf_by_doc {1: [('dog', 3), ('bird', 0)], 2: [('egret', 2), ('cat', 3), ('bird', 0), ('aardvark', 1)], 3: [('fish', 6), ('bird', 0), ('dog', 1), ('aardvark', 5)], 4: [('fish', 6), ('bird', 0), ('dog', 1), ('aardvark', 2)], 5: [('egret', 4), ('bird', 0)], 6: [('bird', 0)], 7: [('dog', 5), ('bird', 0)], 8: [('bird', 0), ('aardvark', 1)]}

dict_of_search = {1: [('bird', 0), ('dog', 1), ('cat', 3)]}

我需要计算 dict_of_search 每把钥匙 dict_of_items ,然后存储生成的点积值并按键跟踪。我的意思是…

项目目录 ,1和中的项 搜索命令 向量为:

|      | dict_of_items_1 | dict_of_search |
|:----:|:---------------:|:--------------:|
| bird |        0        |        0       |
|  dog |        3        |        1       |
|  cat |        0        |        3       |

所以我的点积是: 3

与dict_of_search相比,期望的结果将是dict_of_items及其各自的点积键字典(这将永远只是一个项),按点积降序排序。

但是,我不知道如何将字典的形状转换为两个数组来执行向量计算,特别是当其中一个词不出现时(例如,在上面的示例中),何时处理 cat 未出现在键中 1 在里面 dict_of_items_1 .

我试过这样的方法 numpy

import numpy as numpy

def main():
    test_arr_1 = [1,2,3]
    test_arr_2 = [3,2,6]

    first_dot_product = numpy.dot(test_arr_1, test_arr_2)

    print("First Example: ", first_dot_product)

    test_arr_3 = [3,0,1]
    test_arr_4 = [2,10]

    second_dot_product = numpy.dot(test_arr_3, test_arr_4)

    print("Second Example Missing Value: ", second_dot_product)

main()

但这失败了,因为向量的大小和形状都不一样。

ValueError: shapes (3,) and (2,) not aligned: 3 (dim 0) != 2 (dim 0)

我还尝试将字典值重新格式化为列表:

def main():
    dict_of_items = {'1': [('bird', 0), ('dog', 3), ('egret', 2), ('bird', 0), ('aardvark', 1), ('cat', 3), ('dog', 1), ('bird', 0), ('fish', 6), ('aardvark', 5), ('dog', 1), ('bird', 0), ('fish', 6), ('aardvark', 2), ('egret', 4), ('bird', 0), ('bird', 0), ('bird', 0), ('dog', 5), ('bird', 0), ('aardvark', 1)]}

    test_list_of_lists = []
    for k, v in dict_of_items.items():
        curr_list = []
        for aTuple in v:
            curr_list.append(aTuple[1])
        test_list_of_lists.append(curr_list)

    print(test_list_of_lists)   

main()

但这只是把所有东西错误地合并到一个列表中: [[0, 3, 2, 0, 1, 3, 1, 0, 6, 5, 1, 0, 6, 2, 4, 0, 0, 0, 5, 0, 1]]

我也看了一眼 this post ,但那本字典的格式要简单得多。

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1034 次点击  
文章 [ 2 ]  |  最新文章 4 年前
Dev Khadka
Reply   •   1 楼
Dev Khadka    4 年前

如果你把你的元组转换成下面这样的字典会更容易。然后我们可以用这样的列表理解

dict_of_items = {key:dict(value) for key, value in dict_of_items.items()}
dict_of_search = {key:dict(value) for key, value in dict_of_search.items()}

{item_key: sum([search[key]*item.get(key,0)  for key in search.keys()]) 
     for item_key, item in dict_of_items.items() 
     for search in dict_of_search.values()}

Daniel Mesejo
Reply   •   2 楼
Daniel Mesejo    4 年前

计算上的值的doc乘积 dict_of_search VS dict_of_items ,您可以:

def prod(source, target):
    return sum(source.get(key, 0) * target.get(key, 0) for key in source.keys() | target.keys())


dict_of_items = {1: [('dog', 3), ('bird', 0)], 2: [('egret', 2), ('cat', 3), ('bird', 0), ('aardvark', 1)],
                 3: [('fish', 6), ('bird', 0), ('dog', 1), ('aardvark', 5)],
                 4: [('fish', 6), ('bird', 0), ('dog', 1), ('aardvark', 2)], 5: [('egret', 4), ('bird', 0)],
                 6: [('bird', 0)], 7: [('dog', 5), ('bird', 0)], 8: [('bird', 0), ('aardvark', 1)]}

dict_of_search = {1: [('bird', 0), ('dog', 1), ('cat', 3)]}

for k, v in dict_of_items.items():
    for se in dict_of_search.values():
        print(k, prod(dict(v), dict(se)))

产量

1 3
2 9
3 1
4 1
5 0
6 0
7 5
8 0

如果要将结果存储在字典中,请执行以下操作:

result = {}
for k, v in dict_of_items.items():
    for se in dict_of_search.values():
        result[k] = prod(dict(v), dict(se))

print(result)

产量

{1: 3, 2: 9, 3: 1, 4: 1, 5: 0, 6: 0, 7: 5, 8: 0}