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3.8 operator -- Standard operators as functions.

The operator module exports a set of functions implemented in C 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 class methods; variants without leading and trailing "__" are also provided for convenience.

The operator module defines the following functions:

add (a, b)

__add__ (a, b)

Return a + b, for a and b numbers.

sub (a, b)

__sub__ (a, b)

Return a - b.

mul (a, b)

__mul__ (a, b)

Return a * b, for a and b numbers.

div (a, b)

__div__ (a, b)

Return a / b.

mod (a, b)

__mod__ (a, b)

Return a % b.

neg (o)

__neg__ (o)

Return o negated.

pos (o)

__pos__ (o)

Return o positive.

abs (o)

__abs__ (o)

Return the absolute value of o.

inv (o)

__inv__ (o)

__invert__ (o)

Return the inverse of o. The names invert() and __invert__() were added in Python 2.0.

lshift (a, b)

__lshift__ (a, b)

Return a shifted left by b.

rshift (a, b)

__rshift__ (a, b)

Return a shifted right by b.

and_ (a, b)

__and__ (a, b)

Return the bitwise and of a and b.

or_ (a, b)

__or__ (a, b)

Return the bitwise or of a and b.

xor (a, b)

__xor__ (a, b)

Return the bitwise exclusive or of a and b.

not_ (o)

__not__ (o)

Return the outcome of not o. (Note that there is no __not__() method for object instances; only the interpreter core defines this operation.)

truth (o)

Return 1 if o is true, and 0 otherwise.

concat (a, b)

__concat__ (a, b)

Return a + b for a and b sequences.

repeat (a, b)

__repeat__ (a, b)

Return a * b where a is a sequence and b is an integer.

contains (a, b)

__contains__ (a, b)

Return the outcome of the test b in a. Note the reversed operands. The name __contains__() was added in Python 2.0.

sequenceIncludes (...)

Deprecated since release 2.0. Use contains() instead.Alias for contains().

countOf (a, b)

Return the number of occurrences of b in a.

indexOf (a, b)

Return the index of the first of occurrence of b in a.

getitem (a, b)

__getitem__ (a, b)

Return the value of a at index b.

setitem (a, b, c)

__setitem__ (a, b, c)

Set the value of a at index b to c.

delitem (a, b)

__delitem__ (a, b)

Remove the value of a at index b.

getslice (a, b, c)

__getslice__ (a, b, c)

Return the slice of a from index b to index c-1.

setslice (a, b, c, v)

__setslice__ (a, b, c, v)

Set the slice of a from index b to index c-1 to the sequence v.

delslice (a, b, c)

__delslice__ (a, b, c)

Delete the slice of a from index b to index c-1.

The operator also defines a few predicates to test the type of objects. Note: Be careful not to misinterpret the results of these functions; only isCallable() has any measure of reliability with instance objects. For example:

>>> class C:
...     pass
...
>>> import operator
>>> o = C()
>>> operator.isMappingType(o)
1

isCallable (o)

Deprecated since release 2.0. Use the callable() built-in function instead.Returns true if the object o can be called like a function, otherwise it returns false. True is returned for functions, bound and unbound methods, class objects, and instance objects which support the __call__() method.

isMappingType (o)

Returns true if the object o supports the mapping interface. This is true for dictionaries and all instance objects. Warning: There is no reliable way to test if an instance supports the complete mapping protocol since the interface itself is ill-defined. This makes this test less useful than it otherwise might be.

isNumberType (o)

Returns true if the object o represents a number. This is true for all numeric types implemented in C, and for all instance objects. Warning: There is no reliable way to test if an instance supports the complete numeric interface since the interface itself is ill-defined. This makes this test less useful than it otherwise might be.

isSequenceType (o)

Returns true if the object o supports the sequence protocol. This returns true for all objects which define sequence methods in C, and for all instance objects. Warning: There is no reliable way to test if an instance supports the complete sequence interface since the interface itself is ill-defined. This makes this test less useful than it otherwise might be.

Example: Build a dictionary that maps the ordinals from 0 to 256 to their character equivalents.

>>> import operator
>>> d = {}
>>> keys = range(256)
>>> vals = map(chr, keys)
>>> map(operator.setitem, [d]*len(keys), keys, vals)

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