How do I set default hyperparameter values in a sweep?

You don’t need to provide values for every hyperparameter in a W&B Sweep. You can set defaults and let the sweep override them. Access hyperparameter names and values from the sweep configuration using run.config, which acts like a dictionary. For runs outside a sweep, set run.config values by passing a dictionary to the config argument in wandb.init(). In a sweep, any configuration you pass to wandb.init() serves as a default value that the sweep can override. Use run.config.setdefaults() for explicit behavior. The following code snippets illustrate both methods:

wandb.init()
config.setdefaults()

# Set default values for hyperparameters
config_defaults = {"lr": 0.1, "batch_size": 256}

# Start a run and provide defaults
# that a sweep can override
with wandb.init(config=config_defaults) as run:
    # Add training code here
    ...

# Set default values for hyperparameters
config_defaults = {"lr": 0.1, "batch_size": 256}

# Start a run
with wandb.init() as run:
    # Update any values not set by the sweep
    run.config.setdefaults(config_defaults)

    # Add training code here

Sweeps

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