https://docs.python.org/3/library/functions.html
getattr / hasattr / setattr / delattr
getattr(object, name: str)
hasattr(object, name: str)
delattr(object, name: str)
setattr(object, name: str, value)
class BertModel:
model_name = 'bert'
def __init__(self, config, tokenizer):
self.config = config
self.tokenizer = tokenizer
def forward(self, x: int, y: int):
return x + y
model = BertModel(config='bert_config', tokenizer='bert_tokenizer')
print(getattr(model, 'model_name'))
print(getattr(model, 'config'))
print(getattr(model, 'forward'))
print(getattr(model, 'forward')(1, 2))
bert
bert_config
<bound method BertModel.forward of <__main__.BertModel object at 0x7f763258e2b0>>
3
hasattr(model, 'forward')
True
delattr(model, 'config') # ==> del model.config
hasattr(model, 'config')
False
map / filter / reduce
map(function, iterable, …) # iterable一个或多个
filter(function, iterable)
reduce(function, iterable[, initializer])
mapped = map(lambda x, y: x + y, [1, 2, 3], [4, 5, 6])
mapped
<map at 0x7f76323d5c10>
list(mapped)
[5, 7, 9]
filtered = filter(lambda x: x > 4, [2, 3, 4, 5, 6])
filtered
<filter at 0x7f76318d5040>
list(filtered)
[5, 6]
from functools import reduce
reduced = reduce(lambda x, y: x + y, [1, 2, 3])
reduced
6
zip
zip() 函数用于将可迭代的对象作为参数，将对象中对应的元素打包成一个个元组，然后返回由这些元组组成的列表。
如果各个迭代器的元素个数不一致，则返回列表长度与最短的对象相同，利用 * 号操作符，可以将元组解压为列表。
l1 = [1, 2, 3]
l2 = [4, 5, 6]
l3 = [7, 8, 9, 10]
list(zip(l1))
[(1,), (2,), (3,)]
zipped = zip(l1, l2)
list(zipped)
[(1, 4), (2, 5), (3, 6)]
zipped = zip(l1, l3)
zipped = list(zipped)
zipped
[(1, 7), (2, 8), (3, 9)]
list(zip(*zipped))
[(1, 2, 3), (7, 8, 9)]