更新regex表达式以考虑多种情况

Question

我需要在test_string:中替换-

import re
test_string = "refer- ences har- ness Stand- ard Re- quired www.mypo- rtal.test.com This - is a document"
re.sub(r"[- ]", "", test_string)

预期结果：

references harness Standard Required www.myportal.test.com This - is a document

基本上，只有当-之前没有空白时，才应该进行替换。

我该怎么做？目前我得到的是：

referencesharnessStandardRequiredwww.myportal.test.comThisisadocument

我很感激有人也能解释解决方案(不仅仅是给出正确的正则表达式(

Answer 1

您可以使用

import re
test_string = "refer- ences har- ness Stand- ard Re- quired www.mypo- rtal.test.com This - is a document"
print(re.sub(r"(?<!s)-s+|", "", test_string))
# => references harness Standard Required www.myportal.test.com This - is a document

请参阅regex演示和Python演示。

详细信息

• (?<!s)-一个负查找，如果当前位置左侧有空白，则匹配失败
• --连字符
• s+-一个或多个空白字符

Answer 2

import re
test_string = "refer- ences har- ness Stand- ard Re- quired www.mypo- rtal.test.com This - is a document"
test_string = re.sub(r'[a-zA-Z0-9]- ', '', test_string)
print(test_string)