Type validation#

Configuration types convert given configuration values. Values incompatible with the type are rejected and the user is warned. The default type is str.

Any callable that takes 1 argument can be used as a type handler. The config.types module provides extra functionality such as validation of list and dictionaries and even more complex combinations of types. Every configuration node itself can be used as a type.


All of the members of the config.types module are factory methods: they need to be called in order to produce the type handler. Make sure that you use config.attr(type=types.any_()), as opposed to config.attr(type=types.any_).


from bsb import config
from bsb.config import types

class TestNode
  name = config.attr()

class TypeNode
  # Default string
  some_string = config.attr()
  # Explicit & required string
  required_string = config.attr(type=str, required=True)
  # Float
  some_number = config.attr(type=float)
              # types.float / types.int
  bounded_float = config.attr(type=types.float(min=0.3, max=17.9))
  # Float, int or bool (attempted to cast in that order)
  combined = config.attr(type=types.or_(float, int, bool))
  # Another node
  my_node = config.attr(type=TestNode)
  # A list of floats
  list_of_numbers = config.attr(
  # 3 floats
  list_of_numbers = config.attr(
    type=types.list(type=float, size=3)
              # A scipy.stats distribution
              chi_distr = config.attr(type=types.distribution())
              # A python statement evaluation
              statement = config.attr(type=types.evaluation())
  # Create an np.ndarray with 3 elements out of a scalar
  expand = config.attr(
          expand=lambda s: np.ones(3) * s
  # Create np.zeros of given shape
  zeros = config.attr(
          expand=lambda s: np.zeros(s)
  # Anything
  any_ = config.attr(type=types.any_())
  # One of the following strings: "all", "some", "none"
  give_me = config.attr(type=types.in_(["all", "some", "none"]))
  # The answer to life, the universe, and everything else
  answer = config.attr(type=lambda x: 42)
  # You're either having cake or pie
  cake_or_pie = config.attr(type=lambda x: "cake" if bool(x) else "pie")