WSGIPythonHashSeed

Description:

Set the seed used for Python hash randomisation.

Syntax:

WSGIPythonHashSeed random|0..4294967295

Default:

WSGIPythonHashSeed random

Context:

server config

Sets the seed value used by Python for hash randomisation. This is the embedded equivalent of the -R command-line option to the python executable, or the PYTHONHASHSEED environment variable.

The argument must be either random, in which case Python chooses a random seed value at startup, or an unsigned integer in the range 0 to 4294967295 (i.e. 2**32 - 1).

For example, to make hash output deterministic:

WSGIPythonHashSeed 0

Or to explicitly request randomised hashing (the modern Python default):

WSGIPythonHashSeed random

Hash randomisation affects the iteration order of objects such as dict, set and frozenset when they are keyed by strings or bytes. Setting a fixed seed can be useful for reproducing ordering-dependent test failures, but is generally not needed for production deployments.