读取CSV文件并验证基于UTF-8字符的列

Question

我必须读取一个包含列（PersonName，年龄，地址）的CSV文件，并且必须验证PersonName。 “ PersonName只能包含UTF-8字符。”

我正在使用python3.x，因此打开文件后无法使用解码方法。

请告诉我如何打开和读取文件，以便可以忽略不包含任何UTF-8字符的PersonName，然后我可以移至下一行进行验证。

Answer 1

假设文件的其余部分不需要检查或UTF-8合法（包括ASCII数据），则可以使用encoding='utf-8'和errors='replace' open文件。 这会将所有无效字节（采用UTF-8编码）更改为Unicode替换字符\� 。 另外，要保留数据，您可以使用'surrogateescape'作为errors处理程序，该处理程序使用私有使用的Unicode代码表示原始值，以便以后撤消。 然后，您可以随时检查这些内容：

with open(csvname, encoding='utf-8', errors='replace', newline='') as f:
    for PersonName, age, address in csv.reader(f):
        if '\ufffd' in PersonName:
            continue
        ... PersonName was decoded without errors, so process the row ...

或使用surrogateescape ，可以确保其他字段中的任何非UTF-8数据（如果可能的话）在写入时都被恢复：

with open(incsvname, encoding='utf-8', errors='surrogateescape', newline='') as inf,\
     open(outcsvname, 'w', encoding='utf-8', errors='surrogateescape', newline='') as outf:
    csvout = csv.writer(outf)
    for PersonName, age, address in csv.reader(f):
        try:
            # Check for surrogate escapes, and reject PersonNames containing them
            # Most efficient way to do so is a test encode; surrogates will fail
            # to encode with default error handler
            PersonName.encode('utf-8')
        except UnicodeEncodeError:
            continue  # Had non-UTF-8, skip this row

        ... PersonName was decoded without surrogate escapes, so process the row ...

        # You can recover the original file bytes in your code for a field with:
        #     fieldname.encode('utf-8', errors='surrogateescape')
        # Or if you're just passing data to a new file, write the same strings
        # back to a file opened with the same encoding/errors handling; the surrogates
        # will be restored to their original values:
        csvout.writerow([PersonName, age, address])