python - 从字符串中删除所有标点符号，除非它在数字之间

Question

我有一个包含单词和数字的文本。我将给出一个具有代表性的文本示例:

string = "This is a 1example of the text. But, it only is 2.5 percent of all data"

我想把它转换成类似的东西:

"This is a  1 example of the text But it only is  2.5  percent of all data"

因此删除标点符号(可以是. , 或string.punctuation 中的任何其他符号)并放入连接时数字和单词之间的空格。但在我的示例中，请将 float 保持为 2.5。

我使用了以下代码:

item = "This is a 1example of the text. But, it only is 2.5 percent of all data"
item = ' '.join(re.sub( r"([A-Z])", r" \1", item).split())
# This a start but not there yet !
#item = ' '.join([x.strip(string.punctuation) for x in item.split() if x not in string.digits])
item = ' '.join(re.split(r'(\d+)', item) )
print item

结果是:

 >> "This is a  1 example of the text. But, it only is  2 . 5  percent of all data"

我快到了，但无法弄清楚最后的和平。

Answer 1

您可以像这样使用正则表达式环视:

(?<!\d)[.,;:](?!\d)

Working demo

想法是让一个字符类收集您要替换的标点符号，并使用环视来匹配周围没有数字的标点符号

regex = r"(?<!\d)[.,;:](?!\d)"

test_str = "This is a 1example of the text. But, it only is 2.5 percent of all data"

result = re.sub(regex, "", test_str, 0)

结果是:

This is a 1example of the text But it only is 2.5 percent of all data