python try /除了似乎与KeyError配合使用

Question

尽管我已经使用了尝试/除了数百次以外的条款，但我以前从未见过这样的行为，现在我感到困惑。我可以知道我想念什么吗？

import pandas as pd
import os


season_ep = {}
for season in range(1, 16):
    for ind, row in pd.read_html('https://thetvdb.com/series/curious-george/seasons/official/%d' % season)[0].iterrows():
        season_ep[row['Name']] = row['Unnamed: 0']

errors = []
for root, dirs, files in os.walk("/run/user/1000/gvfs/smb-share:server=nas.local,share=media/TV Shows/Curious George", topdown=False):
    for name in files:
        try:
            to_print = season_ep[name.split('-')[-1][:-4]]
            print(to_print)
        except KeyError:
            errors.append(os.path.join(dirs, name))

for e in errors:
    print('ERROR: %s' % e)

基本上，我正在搜索键'旧麦格吉（McGeorgie）在字典 season_ep 中返回keyError，但我不' t了解为什么我会收到以下错误。我希望零件除零件以识别keyError并接管，并允许代码完全执行。

Traceback (most recent call last):
  File "/home/jthom/PycharmProjects/TVDB_ID/main.py", line 14, in <module>
    to_print = season_ep[name.split('-')[-1][:-4]]
KeyError: 'Old McGeorgie Had a Farm'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
  File "/usr/lib/python3.10/code.py", line 90, in runcode
    exec(code, self.locals)
  File "<input>", line 1, in <module>
  File "/snap/pycharm-community/278/plugins/python-ce/helpers/pydev/_pydev_bundle/pydev_umd.py", line 198, in runfile
    pydev_imports.execfile(filename, global_vars, local_vars)  # execute the script
  File "/snap/pycharm-community/278/plugins/python-ce/helpers/pydev/_pydev_imps/_pydev_execfile.py", line 18, in execfile
    exec(compile(contents+"\n", file, 'exec'), glob, loc)
  File "/home/jthom/PycharmProjects/TVDB_ID/main.py", line 17, in <module>
    errors.append(os.path.join(dirs, name))
  File "/usr/lib/python3.10/posixpath.py", line 76, in join
    a = os.fspath(a)
TypeError: expected str, bytes or os.PathLike object, not list

我正在Ubuntu 22.04上运行Python 3.10.4。感谢您的帮助！

Answer 1

如果您仔细查看堆栈跟踪，您将看到此片段：在处理上述异常时，发生了另一个例外。这告诉您上述keyError被捕获了，但是在execpt块中提出了另一个例外。

解决此问题的最简单方法是添加嵌套try-except：

        try:
            to_print = season_ep[name.split('-')[-1][:-4]]
            print(to_print)
        except KeyError:
            try:
                errors.append(os.path.join(dirs, name))
            except TypeError:
                # handle this error somehow
                pass

您的问题的根源是您将列表传递给

# Delete everything reachable from the directory named in "top",
# assuming there are no symbolic links.
# CAUTION:  This is dangerous!  For example, if top == '/', it
# could delete all your disk files.
import os
for root, dirs, files in os.walk(top, topdown=False):
    for name in files:
        os.remove(os.path.join(root, name))
    for name in dirs:
        os.rmdir(os.path.join(root, name))

​

                errors.append(os.path.join(root, name))

Answer 2

如果您需要收集错误位置列表，则只需要附加路径名root和文件名name

    try:
        to_print = season_ep[name.split('-')[-1][:-4]]
        print(to_print)
    except KeyError:
        #errors.append(os.path.join(dirs, name))
        errors.append(os.path.join(root, name))