<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def exclude(source, keys, *, transform=None):
 """Returns a dictionary excluding keys from a source dictionary. :source: a dictionary :keys: a set of keys, or a predicate function that accepting a key :transform: a function that transforms the values """

  check = keys if callable(keys) else lambda key: key in keys
  return {key: transform(source[key]) if transform else source[key]
          for key in source if not check(key)}