Python has two types of strings: Byte strings, and Unicode strings. On Python 2.x, these were largely interchangeable, but on Python 3, they matter. Mixing them on 2.x can lead to bugs as well.

This document details some key places where string types matter, and serves as a reference while undergoing the porting process to Python 3.

Migrating/Enforcing String Types

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HostingServiceClient

• Request body and headers can be passed in as byte strings or Unicode strings. They're normalized internally to the appropriate string type on each version of Python.
• Response body and headers are always bytes.