""" 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', 'call', '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', '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 items in a which are, or which equal, b." count = 0 for i in a: if i is b or 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 is b or 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 # Other Operations ************************************************************# def call(obj, /, *args, **kwargs): """Same as obj(*args, **kwargs).""" return obj(*args, **kwargs) # 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__(self, name, /, *args, **kwargs): self._name = name if not isinstance(self._name, str): raise TypeError('method name must be a string') self._args = args 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 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_ __call__ = call __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