正则表达式 - 计算一个单词在文本中出现的次数

Question

我要设置的是一个函数，给定特定文本将打印出单词['color', 'Colour', 'Color','Colour']appear 的次数。这样我得到以下结果：

assert colorcount("Color Purple") == 1

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

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

---

我拥有的是

import re

def colorcount(text):

all_matches = re.findall('color', 'Colour', 'Color'. 'Colour', text)

return len(all_matches)

print(colorcount(text)

它不起作用，我该如何编写代码以使其按我想要的方式工作？

Answer 1

您可以简单地将文本转换为特定大小写（即全部小写），然后使用字符串的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

Answer 2

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

哪些输出：

1
2
4

Answer 3

试试这个

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

使用带有标志re.I（不区分大小写）和re.findll 的正则表达式，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'))

打印：

4