There is the corresponding section on the topic here https://github.com/python/cpython/blob/3.6/Doc/library/secrets.rst#how-many-bytes-should-tokens-use

The current value of 32 bytes is mentioned there correctly.

Unfortunately, there is no way to know which constant in the `secrets` stores this value.

It is easy to imagine a use case to use say `DEFAULT_ENTROPY * 4` in the code and stay updated with the default entropy being increased over time.

Thus, it looks reasonable to document the `secrets.DEFAULT_ENTROPY` constant in the module docs.