Troubleshoot MWS Signature Method (XML)

I already tried finding a python developer familiar with the Amazon MWS API without luck. I hope that I can still find someone who can help me trouble shoot a couple of methods in an existing API wrapper.

The wrapper version below works for Python 2.7 but not for Python 3. I made a couple of adjustments but nothing which should cause a signature error.

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The following error response is triggered. As you can tell from the response Amazon did not even bother to adjust error messages between the AWS and MWS Api. Anyway please let me know if you have worked with HMAC before or are ready to try figuring out the errors.

<?xml version="1.0"?>

<ErrorResponse xmlns="[url removed, login to view]">

<Error>

<Type>Sender</Type>

<Code>SignatureDoesNotMatch</Code>

<Message>The request signature we calculated does not match the signature you provided. Check your AWS Secret Access Key and signing method. Consult the service documentation for details.</Message>

</Error>

<RequestID>6f2d00eb-78fd-4ed8-99ce-15d38424fd12</RequestID>

</ErrorResponse>

Amazon Web Services Big Data Sales Python Software Architecture

Project ID: #11718762

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