Magic methods are ways to enhance classes and give them more functionality. They can be used to modify every aspect of a class and how it interacts with other objects. They essentially let you overwrite different aspects of python, you can change what the len() method returns, what happens when it is cast to a string, or what happens when it leaves the current scope.
class magic_methods:
def __new__(cls, x): # called before __init__ and is used to control the creation of a new instance
print("__new__")
inst = object.__new__(cls)
return inst
def __init__(self, x): # called on instantiation of class and is used to control the initialization of a new instance
self.x = x
print("__init__")
# __int__ int(magic_methods)
# __float__ float(magic_methods)
# __complex__ complex(magic_methods)
# __oct__ oct(magic_methods)
# __hex__ hex(magic_methods)
# __index__ list[:magic_methods] used when object is in a slice expression
def __str__(self): # used when converting class to string str(magic_methods)
return "string"
# __repr__ repr(magic_methods)
# __len__ len(magic_methods)
# __unicode__ unicode(magic_methods)
# __format__ string.format(magic_methods)
# __hash__ hash(magic_methods)
# __nonzero__ bool(magic_methods)
# __dir__ dir(magic_methods)
# __sizeof__ sys.getsizeof(magic_methods)
# __pos__ +magic_methods
# __abs__ abs(magic_methods)
# __invert__ ~magic_methods
# __round__ round(magic_methods)
# __floor__ math.floor(magic_methods)
# __ceil__ math.ceil(magic_methods)
# __trunc__ math.trunc(magic_methods)
def __neg__(self): # used when class is negative -magic_methods
return -5
#__contains__ magic_methods in magic_methods
# __sub__ magic_methods - magic_methods
# __mul__ magic_methods * magic_methods
# __floordiv__ magic_methods // magic_methods
# __truediv__ magic_methods / magic_methods
# __mod__ magic_methods % magic_methods
# __power__ magic_methods ** magic_methods
def __add__(self, other): # used when + operator is used on class magic_methods + magic_methods
if type(other) is magic_methods:
return self.x + other.x
return self.x
# __iadd__ magic_methods += magic_methods
# __isub__ magic_methods -= magic_methods
# __imul__ magic_methods *= magic_methods
# __ifloordiv__ magic_methods //= magic_methods
# __idiv__ magic_methods /= magic_methods
# __imod__ magic_methods %= magic_methods
# __ipow__ magic_methods **= magic_methods
# __ilshift__ magic_methods <<= magic_methods
# __irshift__ magic_methods >>= magic_methods
# __iand__ magic_methods &= magic_methods
# __ior__ magic_methods |= magic_methods
# __ixor__ magic_methods ^= magic_methods
# __lt__ magic_methods < magic_methods
# __gt__ magic_methods > magic_methods
# __le__ magic_methods <= magic_methods
# __eq__ magic_methods == magic_methods
# __ne__ magic_methods != magic_methods
def __ge__(self, other): # used when >= operator is used on class magic_methods >= magic_methods
if type(other) is magic_methods:
return self.x >= other.x
def __getattr__(self, attr): # called when trying to access an attribute that does not exist
print("Attribute does not exist")
def __getitem__(self, index): # gets item at class index magic_methods[i]
return index
def __setitem__(self, index, item): # sets item at class index magic_methods[i] = x
self.x = item
def __enter__(self): # called when with magic_method()) as x starts
print("entered")
def __exit__(self, exc_type, exc_val, exc_tb): # called when with magic_method()) as x exits
print("exited")
def __call__(self, x):
return self.x + x
def __del__(self):
print("__del__")
magic = magic_methods(5)
magic2 = magic_methods(10)
print(str(magic)) # string
print(magic + magic2) # 15
print(magic + 2) # 5
print(magic >= magic2) # False
print(-magic) # -5
magic.totallyRealAttribute
print(magic[3]) # 3
with magic_methods(7) as method:
...
print(magic(1)) # 6