对于给定的字符串列表，计算单词数

Question

我有一个给定的字符串列表，它是：

strings = ["the method of lagrange multipliers is the economists workhorse for solving optimization problems", "the technique is a centerpiece of economic theory but unfortunately its usually taught poorly"]

现在我想找出每个句子中的单词号，这样我的输出就会

{'the': 2, 'method': 1, 'of': 1, 'lagrange': 1, 'multipliers': 1, 'is': 1, 'economists': 1, 'workhorse': 1, 'for': 1, 'solving': 1, 'optimization': 1, 'problems': 1}

{'the': 1, 'technique': 1, 'is': 1, 'a': 1, 'centerpiece': 1, 'of': 1, 'economic': 1, 'theory': 1, 'but': 1, 'unfortunately': 1, 'its': 1, 'usually': 1, 'taught': 1, 'poorly': 1}

我的代码如下：

from collections import Counter

dataset = ["the method of lagrange multipliers is the economists workhorse for solving optimization problems",
           "the technique is a centerpiece of economic theory but unfortunately its usually taught poorly"]


for index,row in enumerate(dataset):
    word_frequency = dict(Counter(row.split(" ")))
    
print(word_frequency)

通过这个，我得到的输出是：

{'the': 1, 'technique': 1, 'is': 1, 'a': 1, 'centerpiece': 1, 'of': 1, 'economic': 1, 'theory': 1, 'but': 1, 'unfortunately': 1, 'its': 1, 'usually': 1, 'taught': 1, 'poorly': 1}

很明显，这只是考虑第二句话并计算它，而不是第一句话

有人能帮我理解代码中的错误吗

Answer 1

在循环内打印，而不是在循环内设置变量（在每次迭代结束时打印之前，该变量将被覆盖）：

>>> dataset = ["the method of lagrange multipliers is the economists workhorse for solving optimization problems",
...            "the technique is a centerpiece of economic theory but unfortunately its usually taught poorly"]
>>> from collections import Counter
>>> for sentence in dataset:
...     print(dict(Counter(sentence.split())))
...
{'the': 2, 'method': 1, 'of': 1, 'lagrange': 1, 'multipliers': 1, 'is': 1, 'economists': 1, 'workhorse': 1, 'for': 1, 'solving': 1, 'optimization': 1, 'problems': 1}
{'the': 1, 'technique': 1, 'is': 1, 'a': 1, 'centerpiece': 1, 'of': 1, 'economic': 1, 'theory': 1, 'but': 1, 'unfortunately': 1, 'its': 1, 'usually': 1, 'taught': 1, 'poorly': 1}

Answer 2

正在使用数据集列表中的每个字符串更新word_frequency。最后，它存储数据集中最后一个字符串的计数器。因此，显示最后一个字符串中单词的计数器。您可以在for循环中使用print(word_frequency)，也可以使用list ，每次都将word_frequency附加到列表中，一旦退出循环，只需打印list

from collections import Counter

dataset = ["the method of lagrange multipliers is the economists workhorse for solving optimization problems",
           "the technique is a centerpiece of economic theory but unfortunately its usually taught poorly"]

l = []
for index,row in enumerate(dataset):
    word_frequency = dict(Counter(row.split(" ")))
    l.append(word_frequency)
    
print(l)

Answer 3

只需将打印移动到for循环中，即可覆盖计算的单词频率参数