xlrd - 错误“工作簿已加密”，Python 3.2.3

Question

我有一个简短的程序，用于收集文件夹/子文件夹中所有 .xls 文件的列表，然后循环遍历文件列表，打开每个 xls 文档（尝试： book = xlrd.open_workbook(f) ）以查找特定信息。如果引发异常，我会将文件名写入异常列表。我发现我有很多文件 xlrd 抛出错误：

Traceback (most recent call last):
  File "<pyshell#5>", line 1, in <module>
    book = xlrd.open_workbook(f)
  File "C:\Python32\lib\site-packages\xlrd\__init__.py", line 435, in open_workbook
    ragged_rows=ragged_rows,
  File "C:\Python32\lib\site-packages\xlrd\book.py", line 116, in open_workbook_xls
    bk.parse_globals()
  File "C:\Python32\lib\site-packages\xlrd\book.py", line 1206, in parse_globals
    self.handle_filepass(data)
  File "C:\Python32\lib\site-packages\xlrd\book.py", line 924, in handle_filepass
    raise XLRDError("Workbook is encrypted")
xlrd.biffh.XLRDError: Workbook is encrypted

但我可以毫无问题地使用 Excel 打开文件。有谁知道为什么当文件似乎没有加密时 xlrd 会抛出加密错误？

谢谢，

弗雷德

Answer 1

我遇到了同样的问题，正如 @zindorsky 在他们的评论中提到的那样，当文件具有受保护的工作表时，或者由于 Excel 使用神奇密码静默加密文件的其他原因，可能会发生这种情况VelvetSweatshop。

XLRD 无法自行处理加密文件（事实上，自述文件将其列为“不可能完成”），但最近有另一个 Python 库可以解密各种 MS Office 文件（包括 .xls 文件） - msoff加密工具。

我能够使用它成功解决该问题 - 这是代码的缩写（且未经测试！）片段版本

import xlrd
import msoffcrypto

def handle_protected_workbook(wb_filepath):
    try:
        _book = xlrd.open_workbook(wb_filepath)
    except xlrd.biffh.XLRDError, e:
        if e.message == "Workbook is encrypted":
            # Try and unencrypt workbook with magic password
            wb_msoffcrypto_file = msoffcrypto.OfficeFile(open(wb_filepath, 'rb'))
            try:
                # Yes, this is actually a thing
                # https://nakedsecurity.sophos.com/2013/04/11/password-excel-velvet-sweatshop/
                wb_msoffcrypto_file.load_key(password='VelvetSweatshop')
            except AssertionError, e:
                if e.message == "Failed to verify password":
                    # Encrypted with some other password
                    raise # or do something else
                else:
                    # Some other error occurred
                    raise
            except:
                # Some other error occurred
                raise
            else:
                # Magic Excel password worked

                assert wb_filepath.endswith('.xls')
                wb_unencrypted_filename = wb_filepath[:-(len('.xls'))] + '__unencrypted.xls'

                with tempfile.NamedTemporaryFile() as tmp_wb_unencrypted_file:
                    # Decrypt into the tempfile
                    wb_msoffcrypto_file.decrypt(tmp_wb_unencrypted_file)
                    # --- Do something with the file ---
                # return true to indicate file was touched
                return True  # or do something else
        else:
            # some other xlrd error occurred.
            return False  # or do something else
    except:
        # some non-xlrd error occurred.
        return False  # or do something else