| """ |
| Operator Interface |
| |
| This module exports a set of functions corresponding to the intrinsic |
| operators of Python. For example, operator.add(x, y) is equivalent |
| to the expression x+y. The function names are those used for special |
| methods; variants without leading and trailing '__' are also provided |
| for convenience. |
| |
| This is the pure Python implementation of the module. |
| """ |
| |
| __all__ = ['abs', 'add', 'and_', 'attrgetter', 'concat', 'contains', 'countOf', |
| 'delitem', 'eq', 'floordiv', 'ge', 'getitem', 'gt', 'iadd', 'iand', |
| 'iconcat', 'ifloordiv', 'ilshift', 'imatmul', 'imod', 'imul', |
| 'index', 'indexOf', 'inv', 'invert', 'ior', 'ipow', 'irshift', |
| 'is_', 'is_not', 'isub', 'itemgetter', 'itruediv', 'ixor', 'le', |
| 'length_hint', 'lshift', 'lt', 'matmul', 'methodcaller', 'mod', |
| 'mul', 'ne', 'neg', 'not_', 'or_', 'pos', 'pow', 'rshift', |
| 'setitem', 'sub', 'subscript', 'truediv', 'truth', 'xor'] |
| |
| from builtins import abs as _abs |
| |
| |
| # Comparison Operations *******************************************************# |
| |
| def lt(a, b): |
| "Same as a < b." |
| return a < b |
| |
| def le(a, b): |
| "Same as a <= b." |
| return a <= b |
| |
| def eq(a, b): |
| "Same as a == b." |
| return a == b |
| |
| def ne(a, b): |
| "Same as a != b." |
| return a != b |
| |
| def ge(a, b): |
| "Same as a >= b." |
| return a >= b |
| |
| def gt(a, b): |
| "Same as a > b." |
| return a > b |
| |
| # Logical Operations **********************************************************# |
| |
| def not_(a): |
| "Same as not a." |
| return not a |
| |
| def truth(a): |
| "Return True if a is true, False otherwise." |
| return True if a else False |
| |
| def is_(a, b): |
| "Same as a is b." |
| return a is b |
| |
| def is_not(a, b): |
| "Same as a is not b." |
| return a is not b |
| |
| # Mathematical/Bitwise Operations *********************************************# |
| |
| def abs(a): |
| "Same as abs(a)." |
| return _abs(a) |
| |
| def add(a, b): |
| "Same as a + b." |
| return a + b |
| |
| def and_(a, b): |
| "Same as a & b." |
| return a & b |
| |
| def floordiv(a, b): |
| "Same as a // b." |
| return a // b |
| |
| def index(a): |
| "Same as a.__index__()." |
| return a.__index__() |
| |
| def inv(a): |
| "Same as ~a." |
| return ~a |
| invert = inv |
| |
| def lshift(a, b): |
| "Same as a << b." |
| return a << b |
| |
| def mod(a, b): |
| "Same as a % b." |
| return a % b |
| |
| def mul(a, b): |
| "Same as a * b." |
| return a * b |
| |
| def matmul(a, b): |
| "Same as a @ b." |
| return a @ b |
| |
| def neg(a): |
| "Same as -a." |
| return -a |
| |
| def or_(a, b): |
| "Same as a | b." |
| return a | b |
| |
| def pos(a): |
| "Same as +a." |
| return +a |
| |
| def pow(a, b): |
| "Same as a ** b." |
| return a ** b |
| |
| def rshift(a, b): |
| "Same as a >> b." |
| return a >> b |
| |
| def sub(a, b): |
| "Same as a - b." |
| return a - b |
| |
| def truediv(a, b): |
| "Same as a / b." |
| return a / b |
| |
| def xor(a, b): |
| "Same as a ^ b." |
| return a ^ b |
| |
| # Sequence Operations *********************************************************# |
| |
| def concat(a, b): |
| "Same as a + b, for a and b sequences." |
| if not hasattr(a, '__getitem__'): |
| msg = "'%s' object can't be concatenated" % type(a).__name__ |
| raise TypeError(msg) |
| return a + b |
| |
| def contains(a, b): |
| "Same as b in a (note reversed operands)." |
| return b in a |
| |
| def countOf(a, b): |
| "Return the number of times b occurs in a." |
| count = 0 |
| for i in a: |
| if i == b: |
| count += 1 |
| return count |
| |
| def delitem(a, b): |
| "Same as del a[b]." |
| del a[b] |
| |
| def getitem(a, b): |
| "Same as a[b]." |
| return a[b] |
| |
| def indexOf(a, b): |
| "Return the first index of b in a." |
| for i, j in enumerate(a): |
| if j == b: |
| return i |
| else: |
| raise ValueError('sequence.index(x): x not in sequence') |
| |
| def setitem(a, b, c): |
| "Same as a[b] = c." |
| a[b] = c |
| |
| def length_hint(obj, default=0): |
| """ |
| Return an estimate of the number of items in obj. |
| This is useful for presizing containers when building from an iterable. |
| |
| If the object supports len(), the result will be exact. Otherwise, it may |
| over- or under-estimate by an arbitrary amount. The result will be an |
| integer >= 0. |
| """ |
| if not isinstance(default, int): |
| msg = ("'%s' object cannot be interpreted as an integer" % |
| type(default).__name__) |
| raise TypeError(msg) |
| |
| try: |
| return len(obj) |
| except TypeError: |
| pass |
| |
| try: |
| hint = type(obj).__length_hint__ |
| except AttributeError: |
| return default |
| |
| try: |
| val = hint(obj) |
| except TypeError: |
| return default |
| if val is NotImplemented: |
| return default |
| if not isinstance(val, int): |
| msg = ('__length_hint__ must be integer, not %s' % |
| type(val).__name__) |
| raise TypeError(msg) |
| if val < 0: |
| msg = '__length_hint__() should return >= 0' |
| raise ValueError(msg) |
| return val |
| |
| # Generalized Lookup Objects **************************************************# |
| |
| class attrgetter: |
| """ |
| Return a callable object that fetches the given attribute(s) from its operand. |
| After f = attrgetter('name'), the call f(r) returns r.name. |
| After g = attrgetter('name', 'date'), the call g(r) returns (r.name, r.date). |
| After h = attrgetter('name.first', 'name.last'), the call h(r) returns |
| (r.name.first, r.name.last). |
| """ |
| __slots__ = ('_attrs', '_call') |
| |
| def __init__(self, attr, *attrs): |
| if not attrs: |
| if not isinstance(attr, str): |
| raise TypeError('attribute name must be a string') |
| self._attrs = (attr,) |
| names = attr.split('.') |
| def func(obj): |
| for name in names: |
| obj = getattr(obj, name) |
| return obj |
| self._call = func |
| else: |
| self._attrs = (attr,) + attrs |
| getters = tuple(map(attrgetter, self._attrs)) |
| def func(obj): |
| return tuple(getter(obj) for getter in getters) |
| self._call = func |
| |
| def __call__(self, obj): |
| return self._call(obj) |
| |
| def __repr__(self): |
| return '%s.%s(%s)' % (self.__class__.__module__, |
| self.__class__.__qualname__, |
| ', '.join(map(repr, self._attrs))) |
| |
| def __reduce__(self): |
| return self.__class__, self._attrs |
| |
| class itemgetter: |
| """ |
| Return a callable object that fetches the given item(s) from its operand. |
| After f = itemgetter(2), the call f(r) returns r[2]. |
| After g = itemgetter(2, 5, 3), the call g(r) returns (r[2], r[5], r[3]) |
| """ |
| __slots__ = ('_items', '_call') |
| |
| def __init__(self, item, *items): |
| if not items: |
| self._items = (item,) |
| def func(obj): |
| return obj[item] |
| self._call = func |
| else: |
| self._items = items = (item,) + items |
| def func(obj): |
| return tuple(obj[i] for i in items) |
| self._call = func |
| |
| def __call__(self, obj): |
| return self._call(obj) |
| |
| def __repr__(self): |
| return '%s.%s(%s)' % (self.__class__.__module__, |
| self.__class__.__name__, |
| ', '.join(map(repr, self._items))) |
| |
| def __reduce__(self): |
| return self.__class__, self._items |
| |
| class methodcaller: |
| """ |
| Return a callable object that calls the given method on its operand. |
| After f = methodcaller('name'), the call f(r) returns r.name(). |
| After g = methodcaller('name', 'date', foo=1), the call g(r) returns |
| r.name('date', foo=1). |
| """ |
| __slots__ = ('_name', '_args', '_kwargs') |
| |
| def __init__(*args, **kwargs): |
| if len(args) < 2: |
| msg = "methodcaller needs at least one argument, the method name" |
| raise TypeError(msg) |
| self = args[0] |
| self._name = args[1] |
| if not isinstance(self._name, str): |
| raise TypeError('method name must be a string') |
| self._args = args[2:] |
| self._kwargs = kwargs |
| |
| def __call__(self, obj): |
| return getattr(obj, self._name)(*self._args, **self._kwargs) |
| |
| def __repr__(self): |
| args = [repr(self._name)] |
| args.extend(map(repr, self._args)) |
| args.extend('%s=%r' % (k, v) for k, v in self._kwargs.items()) |
| return '%s.%s(%s)' % (self.__class__.__module__, |
| self.__class__.__name__, |
| ', '.join(args)) |
| |
| def __reduce__(self): |
| if not self._kwargs: |
| return self.__class__, (self._name,) + self._args |
| else: |
| from functools import partial |
| return partial(self.__class__, self._name, **self._kwargs), self._args |
| |
| |
| # In-place Operations *********************************************************# |
| |
| def iadd(a, b): |
| "Same as a += b." |
| a += b |
| return a |
| |
| def iand(a, b): |
| "Same as a &= b." |
| a &= b |
| return a |
| |
| def iconcat(a, b): |
| "Same as a += b, for a and b sequences." |
| if not hasattr(a, '__getitem__'): |
| msg = "'%s' object can't be concatenated" % type(a).__name__ |
| raise TypeError(msg) |
| a += b |
| return a |
| |
| def ifloordiv(a, b): |
| "Same as a //= b." |
| a //= b |
| return a |
| |
| def ilshift(a, b): |
| "Same as a <<= b." |
| a <<= b |
| return a |
| |
| def imod(a, b): |
| "Same as a %= b." |
| a %= b |
| return a |
| |
| def imul(a, b): |
| "Same as a *= b." |
| a *= b |
| return a |
| |
| def imatmul(a, b): |
| "Same as a @= b." |
| a @= b |
| return a |
| |
| def ior(a, b): |
| "Same as a |= b." |
| a |= b |
| return a |
| |
| def ipow(a, b): |
| "Same as a **= b." |
| a **=b |
| return a |
| |
| def irshift(a, b): |
| "Same as a >>= b." |
| a >>= b |
| return a |
| |
| def isub(a, b): |
| "Same as a -= b." |
| a -= b |
| return a |
| |
| def itruediv(a, b): |
| "Same as a /= b." |
| a /= b |
| return a |
| |
| def ixor(a, b): |
| "Same as a ^= b." |
| a ^= b |
| return a |
| |
| |
| @object.__new__ # create a singleton instance |
| class subscript: |
| """ |
| A helper to turn subscript notation into indexing objects. This can be |
| used to create item access patterns ahead of time to pass them into |
| various subscriptable objects. |
| |
| For example: |
| subscript[5] == 5 |
| subscript[3:7:2] == slice(3, 7, 2) |
| subscript[5, 8] == (5, 8) |
| """ |
| __slots__ = () |
| |
| def __new__(cls): |
| raise TypeError("cannot create '{}' instances".format(cls.__name__)) |
| |
| @staticmethod |
| def __getitem__(key): |
| return key |
| |
| @staticmethod |
| def __reduce__(): |
| return 'subscript' |
| |
| |
| try: |
| from _operator import * |
| except ImportError: |
| pass |
| else: |
| from _operator import __doc__ |
| |
| # All of these "__func__ = func" assignments have to happen after importing |
| # from _operator to make sure they're set to the right function |
| __lt__ = lt |
| __le__ = le |
| __eq__ = eq |
| __ne__ = ne |
| __ge__ = ge |
| __gt__ = gt |
| __not__ = not_ |
| __abs__ = abs |
| __add__ = add |
| __and__ = and_ |
| __floordiv__ = floordiv |
| __index__ = index |
| __inv__ = inv |
| __invert__ = invert |
| __lshift__ = lshift |
| __mod__ = mod |
| __mul__ = mul |
| __matmul__ = matmul |
| __neg__ = neg |
| __or__ = or_ |
| __pos__ = pos |
| __pow__ = pow |
| __rshift__ = rshift |
| __sub__ = sub |
| __truediv__ = truediv |
| __xor__ = xor |
| __concat__ = concat |
| __contains__ = contains |
| __delitem__ = delitem |
| __getitem__ = getitem |
| __setitem__ = setitem |
| __iadd__ = iadd |
| __iand__ = iand |
| __iconcat__ = iconcat |
| __ifloordiv__ = ifloordiv |
| __ilshift__ = ilshift |
| __imod__ = imod |
| __imul__ = imul |
| __imatmul__ = imatmul |
| __ior__ = ior |
| __ipow__ = ipow |
| __irshift__ = irshift |
| __isub__ = isub |
| __itruediv__ = itruediv |
| __ixor__ = ixor |