python - 将 Fernet key 写入文本文件会生成字节字符串而不是 ASCII 字符串

Question

我正在尝试将使用 python 加密模块( https://cryptography.io/en/latest/ )生成的 Fernet key 写入 .txt 文件。然后读取该 .txt 文件以检索 key 。

from cryptography.fernet import Fernet
import csv
#Creates textfile if textfile has not been created
with open("Keys.txt", "w+") as csvfile:
    csvfile.close()
with open("Keys.txt","rU") as csvfile:
    reader=csv.reader(csvfile)
    KeyFound=0
    for row in reader:
        if len(row)>0:
            KeyFound=1
            Key=row
            print(Key)
        else:
            pass
    if KeyFound==0:
        Key = Fernet.generate_key()
        print(Key)
        print("Created Key")
        csvfile.close()
#Writing Key to textfile
if KeyFound==0:
    with open("Keys.txt", "w+") as csvfile:
        writer=csv.writer(csvfile)
        writer.writerow(Key)
        csvfile.close()

但是，当我运行此代码时，它会生成一个 bytes 字符串而不是 key 。

示例:Fernet key :b'jDyzNLo3aPD6-zFGVRnzMyBdyy93wQhemJ8QR4VH2I0='写成:106,68,121,122,78,76,111,51,97,80,68,54,45,122,70,71,86,82,110,122,77,121,66,100,121,121,57,51,119,81,104,101,109,74,56 ,81,82,52 ,86,72,50,73,48,61

我希望 .txt 文件包含 key :b'jDyzNLo3aPD6-zFGVRnzMyBdyy93wQhemJ8QR4VH2I0='

我对这个问题做了一些研究，我知道 b' 表示一个字节字符串，但我仍然不知道为什么它被表示为字节数字列表而不是 b'jDyzNLo3aPD6-zFGVRnzMyBdyy93wQhemJ8QR4VH2I0='

我知道将 key 保存到 .txt 文件可能不是最安全的方法，因此欢迎任何其他方法。

Answer 1

发生这种情况是因为这是预期的行为。来自Python csv official docs

Writer Objects

Writer objects (DictWriter instances and objects returned by the writer() function) have the following public methods. A row must be an iterable of strings or numbers for Writer objects and a dictionary mapping fieldnames to strings or numbers (by passing them through str() first) for DictWriter objects.

尝试使用 DictWriter(和 DictReader)

with open("Keys.txt", "w+") as csvfile:
    headers = ['key']
    writer=csv.DictWriter(csvfile, fieldnames=headers)
    writer.writeheader()
    writer.writerow({'key': b'jDyzNLo3aPD6-zFGVRnzMyBdyy93wQhemJ8QR4VH2I0='})
    csvfile.close()