In Python, bool() is a built-in function used to convert a value to bool type. The bool() function returns one of two values: True or False.

The bool() function can accept any type of data as argument. It returns False when the argument is:

  • False
  • 0 (including 0L and 0.0)
  • Empty strings '', empty lists [], empty dictionaries {}, empty tuples (), empty sets set()
  • None

All other values will be converted to True, including non-empty strings, non-empty lists, non-empty dictionaries, non-empty tuples, non-empty sets, non-zero numbers, and non-empty objects.

For example:

print(bool(0))       # False
print(bool(3.14))    # True
print(bool(''))      # False
print(bool('abc'))   # True
print(bool([]))      # False
print(bool([1,2,3])) # True
print(bool({}))      # False
print(bool({'a':1})) # True
print(bool(()))      # False
print(bool((1,2,3))) # True
print(bool(set()))   # False
print(bool({1,2,3})) # True
print(bool(None))    # False

Note that the bool() function doesn't forcefully convert the argument to bool type, but rather returns the appropriate result based on the argument's type and value.