Python将UTF-8 w/ BOM转换为UTF-8 w/o BOM

按UTF-8 w/ BOM读入文件，再用UTF-8存储。如果源文件不是UTF-8 w/ BOM或UTF-8 w/o BOM编码，会抛出异常并打印文件全路径，但程序不会终止。

import os

def convert(d):
    for f in os.listdir(d):
        full = os.path.join(d, f)
        if os.path.isfile(full):
            try:
                s = open(full, mode='r', encoding='utf-8-sig').read()
                open(full, mode='w', encoding='utf-8').write(s)
            except Exception as e:
                print(f'ERROR: Non UTF-8 encoded file found: {full}')
        if os.path.isdir(full):
            convert(full)