descriptor 'decode' requires a 'bytes' object but received a 'NoneType'

记录在使用python过程中踩的坑------

使用xlwt库对excel文件进行保存时报错 descriptor 'decode' requires a 'bytes' object but received a 'NoneType'

log:

Traceback (most recent call last):

File "F:/xxxxxx/util/ExcelUtil.py", line 110, in

excel = write_excel("Outbound_Template.xls", 4, 9, "AT2019110912")

File "F:/xxxxxx/util/ExcelUtil.py", line 48, in write_excel

newWb.save(excel_path)

File "F:\Python\lib\site-packages\xlwt\Workbook.py", line 710, in save

doc.save(filename_or_stream, self.get_biff_data())

File "F:\Python\lib\site-packages\xlwt\Workbook.py", line 667, in get_biff_data

before += self.__all_fonts_num_formats_xf_styles_rec()

File "F:\Python\lib\site-packages\xlwt\Workbook.py", line 570, in __all_fonts_num_formats_xf_styles_rec

return self.__styles.get_biff_data()

File "F:\Python\lib\site-packages\xlwt\Style.py", line 185, in get_biff_data

result += self._all_num_formats()

File "F:\Python\lib\site-packages\xlwt\Style.py", line 209, in _all_num_formats

result += NumberFormatRecord(fmtidx, fmtstr).get()

File "F:\Python\lib\site-packages\xlwt\BIFFRecords.py", line 785, in init

ufmtstr = upack2(fmtstr)

File "F:\Python\lib\site-packages\xlwt\UnicodeUtils.py", line 50, in upack2

us = unicode(s, encoding)

TypeError: descriptor 'decode' requires a 'bytes' object but received a 'NoneType'

1.原文件用MS Excel编辑，后执行程序，可以运行

2.原文件用MS Excel编辑，后执行程序，更新后的文件，再用MS Excel编辑，保存，再执行程序，出现上面的错误

我的代码：

# coding:utf-8

def write_excel(file_name, row, col, value, sheet_name="Template"):

    excel_path = Configure.read_config("project_path", "path") + "\\data\\" + file_name

    # formatting_info = True，得以保存之前数据的格式

    old_wb = open_workbook(excel_path, formatting_info=True)

    # 将操作文件对象拷贝，变成可写的workbook对象

    new_wb = copy(old_wb)

    # 获得sheet的对象

    new_ws = new_wb.get_sheet(sheet_name)

    # 写入数据

    new_ws.write(row, col, value)

    # 另存为excel文件，并将文件命名

    new_wb.save(excel_path)

原因：

用xlutils.copy 得到的excel文件，编码格式变了。然后用Office365或WPS去编辑再保存，得到的文件，decode会是None，xlwt save时会出错。（UnicodeUtils.py中的upack2没有考虑到会有None的情况，网上有的解决方式是自己在源码里加多判断None的情况）

源码：

def upack2(s, encoding='ascii'):

    # If not unicode, make it so.

    if isinstance(s, unicode_type):

        us = s

    else:

        us = unicode(s, encoding)

    # Limit is based on number of content characters

    # (not on number of bytes in packed result)

    len_us = len(us)

    if len_us > 32767:

        raise Exception('String longer than 32767 characters')

    try:

        encs = us.encode('latin1')

        # Success here means all chars are in U+0000 to U+00FF

        # inclusive, meaning that we can use "compressed format".

        flag = 0

        n_items = len_us

    except UnicodeEncodeError:

        encs = us.encode('utf_16_le')

        flag = 1

        n_items = len(encs) // 2

        # n_items is the number of "double byte characters" i.e. MS C wchars

        # Can't use len(us).

        # len(u"\U0001D400") -> 1 on a wide-unicode build

        # and 2 on a narrow-unicode build.

        # We need n_items == 2 in this case.

    return pack('<HB', n_items, flag) + encs

解决方法：用OpenOffice去编辑文件保存就不会有问题

巴特西

descriptor 'decode' requires a 'bytes' object but received a 'NoneType'

最新文章

热门文章