Question

我有一个文本，其中我计算了单词的数量和单词的频率。现在，我必须显示前7个百分比。我不知道该怎么做。我知道如何计算部分/整体的百分比，但不确定如何编写代码。我已经在下面按值进行了排序。

def word_frequency():
"""
Function for word frequency
"""
d = dict()

with open(TEXT, "r") as f:
    for line in f:
        words = line.split()
        for w in words:
            if w in d:
                d[w] += 1
            else:
                d[w] = 1

    dict_list = sorted(d.items(), key = itemgetter(1), reverse = True)
    print(dict_list[0:7])

这给了我这个清单：

[('the', 12), ('to', 8), ('of', 6), ('and', 5), ('a', 4), ('in', 4), ('Phil', 3)]

但是如何计算它们并用百分比而不是值显示？文本的字数为199。

致谢

编辑：新修订的密码

def word_frequency():
"""
Function for word frequency
"""
d = dict()

with open(TEXT, "r") as f:
    for line in f:
        words = line.split()
        for w in words:
            if w in d:
                d[w] += round(1/1.99, 1)
            else:
                d[w] = round(1/1.99, 1)

    dict_list = sorted(d.items(), key = itemgetter(1), reverse = True)
    print(dict_list[0:7])

给我这个清单：

[('the', 6.0), ('to', 4.0), ('of', 3.0), ('and', 2.5), ('a', 2.0), ('in', 2.0), ('Phil', 1.5)]

我现在有百分之几的百分比，但是有没有一种更好的方式显示它呢？喜欢：

the 6%
to 4%
of 3%
and 2.5%
a 2%
in 2%
Phil 1.5%

Answer 1

或者，您可以使用Counter中的collections来计算单词的频率。

from operator import itemgetter
from collections import Counter

def most_common(instances):
    """Returns a list of (instance, count) sorted in total order and then from most to least common"""
    return sorted(sorted(Counter(instances).items(), key=itemgetter(0)), key=itemgetter(1), reverse=True)

利用该most_common函数，您可以像您所说的“计算百分比，部分/全部” 一样进行操作。您可以通过遍历单词及其频率并将其除以单词总数来完成操作。

# words = list of strings
frequencies = most_common(words)
percentages = [(instance, count / len(words)) for instance, count in frequencies]

根据您的用例，re.findall(r"\w+", text)可能不是提取单词的最佳方法。

要获得前7个单词，可以通过执行percentages来对percentages[:7]进行切片。

import re

text = "Alice opened the door and found that it led into a small passage, not much larger than a rat-hole: she knelt down and looked along the passage into the loveliest garden you ever saw."

words = re.findall(r"\w+", text)
frequencies = most_common(words)
percentages = [(instance, count / len(words)) for instance, count in frequencies]

for word, percentage in percentages[:7]:
    print("%s %.2f%%" % (word, percentage * 100))

哪个输出：

the 8.57%
a 5.71%
and 5.71%
into 5.71%
passage 5.71%
Alice 2.86%
along 2.86%

如果您希望在不同的大小写中使用相同的单词，则应将其视为相同。然后，您可以在调用most_common之前对所有单词进行归一化。

import unicodedata

def normalize_caseless(text):
    return unicodedata.normalize("NFKD", text.casefold())

然后：

words = ...

成为：

words = list(map(normalize_caseless, ...))

然后在不同的大小写中包含相同单词的字符串，如下所示：

text = "Hello Test test TEST test TeSt"

结果：

test 83.33%
hello 16.67%

代替：

test 33.33%
Hello 16.67%
TEST 16.67%
TeSt 16.67%
Test 16.67%

Answer 2

您可以列举字典中的项目

for k, v in dict_list.items():
    percent = str(v) + ' %'
    result = k + ' ' + percent
    print(result)

Python-以百分比计算词频

2 个答案: