python中怎么得到这个Signature

Signature = base64(hmac-sha1(AccessKeySecret,
METHOD + "\n"
+ ESCAPED_PATH + "\n"
+ ESCAPED_QUERY_STRING + "\n"
+ Content-MD5 + "\n"
+ Content-Type + "\n"
+ Date + "\n"
+ Nonce + "\n"
+ SignedHeaders + "\n"
+ CanonicalizedHeaders))

https://blog.csdn.net/shanlianting/article/details/53308881