Python:遍历多个文本文件,提取目标字符串,并将其附加到列表中

(Python 3.6.3)

这是我的代码:

ip_address = []
dates = []

for subdir, dirs, files in os.walk(rootdir):
    for file in files:
        if file.endswith('.txt'):
            text_data = open(os.path.join(subdir, file))
            ip_address.append(re.findall( r'[0-9]+(?:\.[0-9]+){3}', text_data))
            dates.append(re.findall( r'[0-9]+(?:\/[0-9]+){2}', text_data))
        else:
            pass

TypeError                                 Traceback (most recent call last)
<ipython-input-28-de806e6c6270> in <module>()
      6         if file.endswith('.txt'):
      7             text_data = open(os.path.join(subdir, file))
----> 8             ip_address.append(re.findall( r'[0-9]+(?:\.[0-9]+){3}', text_data))
      9             dates.append(re.findall( r'[0-9]+(?:\/[0-9]+){2}', text_data))
     10         else:

C:\Users\591159\AppData\Local\Continuum\Anaconda3\lib\re.py in findall(pattern, string, flags)
    220 
    221     Empty matches are included in the result."""
--> 222     return _compile(pattern, flags).findall(string)
    223 
    224 def finditer(pattern, string, flags=0):

TypeError: expected string or bytes-like object

我假设我试图提取的数据不是字符串形式,但不完全理解它的含义。我很欣赏任何指向正确方向的指针。非常感谢。