正则表达式 - 计算一个单词在文本中出现的次数

Question

我想要设置的是一个函数，给定某个文本将打印出该单词出现的次数['color', 'Colour', 'Color','Colour']。这样我得到以下结果：assert colorcount("Color Purple") == 1assert colorcount("Your colour is better than my colour") == 2assert colorcount("color Color colour Colour") == 4我拥有的是import redef colorcount(text):all_matches = re.findall('color', 'Colour', 'Color'. 'Colour', text)return len(all_matches)print(colorcount(text)它不起作用，那么我怎样才能编写代码让它按照我想要的方式工作呢？

Answer 1

如果你想使用正则表达式，你可以这样做：

import re

def colorcount(text):

  r = re.compile(r'\bcolour\b | \bcolor\b', flags = re.I | re.X)

  count = len(r.findall(text))

  print(count)

  return count

# These asserts work as expected without raising an AssertionError.

assert colorcount("Color Purple") == 1

assert colorcount("Your colour is better than my colour") == 2

assert colorcount("color Color colour Colour") == 4

哪个输出：

1

2

4

Answer 2

使用以下带有标志的正则表达式re.I（不区分大小写），re.findll然后返回返回列表的长度：

\bcolou?r\b

import re

def colorcount(text):

  return len(re.findall(r'\bcolou?r\b', text, flags=re.I))

print(colorcount('color Color colour Colour'))

印刷：

4

Answer 3

尝试这个

def colorcount(text):

    return len(re.findall('[c|C]olou{0,1}r', text))

assert colorcount("Color Purple") == 1

assert colorcount("Your colour is better than my colour") == 2

assert colorcount("color Color colour Colour") == 4

Answer 4

您可以简单地将文本转换为特定大小写（即全部小写），然后使用字符串count()循环每次出现的关键字：

def colorcount(text):

    KEY_WORDS = [ 'color', 'colour' ]

    counter = 0

    sanitexed_text = text.lower()

    for kw in KEY_WORDS:

        counter += sanitexed_text.count(kw.lower())

    return counter

text = 'color ds das Colour dsafasft e re Color'

# 3

print(colorcount(text))

# All following asserts pass

assert colorcount("Color Purple") == 1

assert colorcount("Your colour is better than my colour") == 2

assert colorcount("color Color colour Colour") == 4