pg.apply_wrappers¶

Accessible via pg.apply_wrappers, pg.symbolic.apply_wrappers.

apply_wrappers(wrapper_classes=None, where=None)[source]¶

Context manager for swapping user classes with their class wrappers.

This helper method is a handy tool to swap user classes with their wrappers within a code block, without modifying exisiting code.

For example:

def foo():
  return A()

APrime = pg.wrap(A)

with pg.apply_wrappers([APrime]):
  # Direct creation of an instance of `A` will be detoured to `APrime`.
  assert isinstance(A(), APrime)

  Indirect creation of an instance of `A` will be detoured too.
  assert isinstance(foo(), APrime)

# Out of the scope, direct/indirect creation `of` A will be restored.
assert not isinstance(A(), APrime)
assert not isinstance(foo(), APrime)

pg.apply_wrappers can be nested, under which the inner context will apply the wrappers from the outter context. pg.apply_wrappers is NOT thread-safe.

Parameters:

wrapper_classes – Wrapper classes to use. If None, sets it to all registered wrapper classes.
where – An optional filter function in signature (wrapper_class) -> bool. If not None, only filtered wrapper_class will be swapped.

Returns:

A context manager that detours the original classes to the wrapper classes.