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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