Question

我有一个Python函数，用于将文本文件写入新文件夹或现有文件夹。问题是我第一次运行该函数时，当文件夹不存在时，我得到一个TypeError：对象类型＆＃39; NoneType＆＃39;没有len（）。我第二次运行它，在创建文件夹后，它工作正常。

import os

def save_string_to_folder(new_folder, string):
    folder_path = 'C:\Users\e6082493\Documents\Improve\Python\Scraping\Folder_%s' % (new_folder)
    if not os.path.exists(folder_path):
        folder_path = os.makedirs(folder_path)
    join_path = os.path.join(folder_path, string)
    join_path_finish = open(join_path, "w")
    join_path_finish.close()


save_string_to_folder('new', 'TextFile.txt')

我会想到我的＆＃39; if＆＃39;声明将纠正此错误。我似乎无法弄清楚我失踪的那一步。谢谢。

这是追溯：

Traceback (most recent call last):
  File "new_2.py", line 12, in <module>
    save_string_to_folder('new', 'TextFile.txt')
  File "new_2.py", line 7, in save_string_to_folder
    join_path = os.path.join(folder_path, string)
   File "C:\Python27\lib\ntpath.py", line 65, in join
result_drive, result_path = splitdrive(path)
  File "C:\Python27\lib\ntpath.py", line 115, in splitdrive
    if len(p) > 1:
TypeError: object of type 'NoneType' has no len()
PS C:\Users\e6082493\Documents\ImproveBKFS\Python\Scraping>

Answer 1

函数os.makedirs不会返回任何内容。将os.makedirs函数调用的返回值分配给folder_path时，它现在包含<class 'NoneType'>。以下代码应按预期工作。

import os

def save_string_to_folder(new_folder, string):
    folder_path = 'C:\Users\e6082493\Documents\Improve\Python\Scraping\Folder_%s' % (new_folder)
    if not os.path.exists(folder_path):
        os.makedirs(folder_path) # Removed the assignment
    join_path = os.path.join(folder_path, string)
    join_path_finish = open(join_path, "w")
    join_path_finish.close()


save_string_to_folder('new', 'TextFile.txt')

从第二次起，该文件夹已经创建，因此它不会进入if条件并删除变量folder_path中的有效路径

写入新文件夹或现有文件夹

1 个答案: