sre_constants.error：无效的组引用

Question

我有多个regEx模式，我希望在文本中匹配它们以在它们周围添加空格..

import re

regList = [r'(#\w+)',r'\d{1,}\.\d{1,}']
#     for  Hashtags , decimal_numbers

str = '22.21@122122.# #fdsf21.ddcf'    
for reg in regList:
    s = re.sub(reg, r' \1 ', str)
    str = s
    print(str)

当我明确地调用regList的一个项目时：

s = re.sub(regList[0], r' \1 ', str)

代码正常运行，否则会出现错误：

22.21@122122.#  #fdsf21 .ddcf
Traceback (most recent call last):
  File "C:\Python35\lib\sre_parse.py", line 938, in expand_template
    literals[index] = g(group) or empty
IndexError: no such group

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "D:/OneDrive/PhD/Tasks & activities/Courses/computational liguistic/P1/py_File/ssssssssssssssssssssss.py", line 8, in <module>
    s = re.sub(reg, r' \1 ', str)
  File "C:\Python35\lib\re.py", line 182, in sub
    return _compile(pattern, flags).sub(repl, string, count)
  File "C:\Python35\lib\re.py", line 330, in filter
    return sre_parse.expand_template(template, match)
  File "C:\Python35\lib\sre_parse.py", line 940, in expand_template
    raise error("invalid group reference")
sre_constants.error: invalid group reference