operator库常用方法
| Function | Syntax |
| add(a+b) | a + b |
| concat(seq1,seq2) | seq1 + seq2 |
| contains(seq, obj) | obj in seq |
| div(a,b)(without future.division) | a/b |
| truediv(a,b)(with future.division) | a/b |
| floordiv(a,b) | a // b |
| and_(a,b) | a & b |
| xor(a, b) | a ^ b |
| invert(a) | ~a |
| or_(a, b) | a b |
| pow(a,b) | a ** b |
| is_(a,b) | a is b |
| is_not(a,b) | a is not b |
| setitem(obj, k, v) | obj[k] = val |
| delitem(obj, k) | del obj[k] |
| getitem(obj, k) | obj[k] |
| lshift(a,b) | a << b |
| mod(a,b) | a % b |
| mul(a,b) | a * b |
| neg(a) | -a |
| not_(a) | not a |
| pos(a) | + a |
| rshift(a, b) | a >> b |
| repeat(seq,i) | seq * i |
| setitem(seq, slice(i,j),values) | seq[i,j] =values |
| delitem(seq,slice(i,j),values) | del seq[i,j] |
| getitem(seq, slice(i,j)) | seq[i:j] |
| mod(s, obj) | s % obj |
| sub(a, b) | a-b |
| truth(obj) | obj |
operator.itemgetter
返回一个可调用对象，获取项目使用的操作数的__getitem__()方法操作数。如果指定了多个项，则返回一个查找值元组。
def itemgetter(*items): if len(items) == 1: item = items[0] def g(obj): return obj[item] else: def g(obj): return tuple(obj[item] for item in items) return g
>>> itemgetter(1)('ABCDEFG')
'B'
>>> itemgetter(1,3,5)('ABCDEFG')
('B', 'D', 'F')
>>> itemgetter(slice(2,None))('ABCDEFG')
'CDEFG'
operator.attrgetter
返回一个可调用对象,通过其操作数获取属性。如果请求多个属性，则返回一个属性元组。属性名称也可以包含点。
def attrgetter(*items): if any(not isinstance(item, str) for item in items): raise TypeError('attribute name must be a string') if len(items) == 1: attr = items[0] def g(obj): return resolve_attr(obj, attr) else: def g(obj): return tuple(resolve_attr(obj, attr) for attr in items) return g def resolve_attr(obj, attr): for name in attr.split("."): obj = getattr(obj, name) return obj