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authorAntoine Pitrou <solipsis@pitrou.net>2013-04-20 17:21:44 (GMT)
committerAntoine Pitrou <solipsis@pitrou.net>2013-04-20 17:21:44 (GMT)
commita85017fbe3be978a6f138662c6cd21052355ef91 (patch)
tree98eea2a8daaa747a4dca3e013c21f1926bcd9eea /Lib/operator.py
parentc9f5ca232acccf412ef14aa294afd9deef4af93d (diff)
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Issue #16694: Add a pure Python implementation of the operator module.
Patch by Zachary Ware.
Diffstat (limited to 'Lib/operator.py')
-rw-r--r--Lib/operator.py412
1 files changed, 412 insertions, 0 deletions
diff --git a/Lib/operator.py b/Lib/operator.py
new file mode 100644
index 0000000..ee81266
--- /dev/null
+++ b/Lib/operator.py
@@ -0,0 +1,412 @@
+#!/usr/bin/env python3
+"""
+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', 'imod', 'imul', 'index',
+ 'indexOf', 'inv', 'invert', 'ior', 'ipow', 'irshift', 'is_',
+ 'is_not', 'isub', 'itemgetter', 'itruediv', 'ixor', 'le',
+ 'length_hint', 'lshift', 'lt', '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 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).
+ """
+ def __init__(self, attr, *attrs):
+ if not attrs:
+ if not isinstance(attr, str):
+ raise TypeError('attribute name must be a string')
+ names = attr.split('.')
+ def func(obj):
+ for name in names:
+ obj = getattr(obj, name)
+ return obj
+ self._call = func
+ else:
+ getters = tuple(map(attrgetter, (attr,) + attrs))
+ def func(obj):
+ return tuple(getter(obj) for getter in getters)
+ self._call = func
+
+ def __call__(self, obj):
+ return self._call(obj)
+
+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])
+ """
+ def __init__(self, item, *items):
+ if not items:
+ def func(obj):
+ return obj[item]
+ self._call = func
+ else:
+ 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)
+
+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).
+ """
+
+ 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]
+ self._args = args[2:]
+ self._kwargs = kwargs
+
+ def __call__(self, obj):
+ return getattr(obj, self._name)(*self._args, **self._kwargs)
+
+# 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 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_
+__floordiv__ = floordiv
+__index__ = index
+__inv__ = inv
+__invert__ = invert
+__lshift__ = lshift
+__mod__ = mod
+__mul__ = mul
+__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
+__ior__ = ior
+__ipow__ = ipow
+__irshift__ = irshift
+__isub__ = isub
+__itruediv__ = itruediv
+__ixor__ = ixor