Trinkle23897 d2b2fa87c0 fix #56
2020-05-29 08:03:37 +08:00

204 lines
7.3 KiB
Python

import torch
import pprint
import numpy as np
from typing import Any, List, Union, Iterator, Optional
class Batch(object):
"""Tianshou provides :class:`~tianshou.data.Batch` as the internal data
structure to pass any kind of data to other methods, for example, a
collector gives a :class:`~tianshou.data.Batch` to policy for learning.
Here is the usage:
::
>>> import numpy as np
>>> from tianshou.data import Batch
>>> data = Batch(a=4, b=[5, 5], c='2312312')
>>> data.b
[5, 5]
>>> data.b = np.array([3, 4, 5])
>>> print(data)
Batch(
a: 4,
b: array([3, 4, 5]),
c: '2312312',
)
In short, you can define a :class:`Batch` with any key-value pair. The
current implementation of Tianshou typically use 7 reserved keys in
:class:`~tianshou.data.Batch`:
* ``obs`` the observation of step :math:`t` ;
* ``act`` the action of step :math:`t` ;
* ``rew`` the reward of step :math:`t` ;
* ``done`` the done flag of step :math:`t` ;
* ``obs_next`` the observation of step :math:`t+1` ;
* ``info`` the info of step :math:`t` (in ``gym.Env``, the ``env.step()``\
function return 4 arguments, and the last one is ``info``);
* ``policy`` the data computed by policy in step :math:`t`;
:class:`~tianshou.data.Batch` has other methods, including
:meth:`~tianshou.data.Batch.__getitem__`,
:meth:`~tianshou.data.Batch.__len__`,
:meth:`~tianshou.data.Batch.append`,
and :meth:`~tianshou.data.Batch.split`:
::
>>> data = Batch(obs=np.array([0, 11, 22]), rew=np.array([6, 6, 6]))
>>> # here we test __getitem__
>>> index = [2, 1]
>>> data[index].obs
array([22, 11])
>>> # here we test __len__
>>> len(data)
3
>>> data.append(data) # similar to list.append
>>> data.obs
array([0, 11, 22, 0, 11, 22])
>>> # split whole data into multiple small batch
>>> for d in data.split(size=2, shuffle=False):
... print(d.obs, d.rew)
[ 0 11] [6 6]
[22 0] [6 6]
[11 22] [6 6]
"""
def __init__(self, **kwargs) -> None:
super().__init__()
self._meta = {}
for k, v in kwargs.items():
if isinstance(v, (list, np.ndarray)) \
and len(v) > 0 and isinstance(v[0], dict) and k != 'info':
self._meta[k] = list(v[0].keys())
for k_ in v[0].keys():
k__ = '_' + k + '@' + k_
self.__dict__[k__] = np.array([
v[i][k_] for i in range(len(v))
])
elif isinstance(v, dict):
self._meta[k] = list(v.keys())
for k_ in v.keys():
k__ = '_' + k + '@' + k_
self.__dict__[k__] = v[k_]
else:
self.__dict__[k] = kwargs[k]
def __getitem__(self, index: Union[str, slice]) -> Union['Batch', dict]:
"""Return self[index]."""
if isinstance(index, str):
return self.__getattr__(index)
b = Batch()
for k in self.__dict__:
if k != '_meta' and self.__dict__[k] is not None:
b.__dict__.update(**{k: self.__dict__[k][index]})
b._meta = self._meta
return b
def __getattr__(self, key: str) -> Union['Batch', Any]:
"""Return self.key"""
if key not in self._meta:
if key not in self.__dict__:
raise AttributeError(key)
return self.__dict__[key]
d = {}
for k_ in self._meta[key]:
k__ = '_' + key + '@' + k_
d[k_] = self.__dict__[k__]
return Batch(**d)
def __repr__(self) -> str:
"""Return str(self)."""
s = self.__class__.__name__ + '(\n'
flag = False
for k in sorted(list(self.__dict__) + list(self._meta)):
if k[0] != '_' and (self.__dict__.get(k, None) is not None or
k in self._meta):
rpl = '\n' + ' ' * (6 + len(k))
obj = pprint.pformat(self.__getattr__(k)).replace('\n', rpl)
s += f' {k}: {obj},\n'
flag = True
if flag:
s += ')'
else:
s = self.__class__.__name__ + '()'
return s
def keys(self) -> List[str]:
"""Return self.keys()."""
return sorted([
i for i in self.__dict__ if i[0] != '_'] + list(self._meta))
def values(self) -> List[Any]:
"""Return self.values()."""
return [self[k] for k in self.keys()]
def get(self, k: str, d: Optional[Any] = None) -> Union['Batch', Any]:
"""Return self[k] if k in self else d. d defaults to None."""
if k in self.__dict__ or k in self._meta:
return self.__getattr__(k)
return d
def to_numpy(self) -> np.ndarray:
"""Change all torch.Tensor to numpy.ndarray. This is an inplace
operation.
"""
for k in self.__dict__:
if isinstance(self.__dict__[k], torch.Tensor):
self.__dict__[k] = self.__dict__[k].cpu().numpy()
def append(self, batch: 'Batch') -> None:
"""Append a :class:`~tianshou.data.Batch` object to current batch."""
assert isinstance(batch, Batch), 'Only append Batch is allowed!'
for k in batch.__dict__:
if k == '_meta':
self._meta.update(batch._meta)
continue
if batch.__dict__[k] is None:
continue
if not hasattr(self, k) or self.__dict__[k] is None:
self.__dict__[k] = batch.__dict__[k]
elif isinstance(batch.__dict__[k], np.ndarray):
self.__dict__[k] = np.concatenate([
self.__dict__[k], batch.__dict__[k]])
elif isinstance(batch.__dict__[k], torch.Tensor):
self.__dict__[k] = torch.cat([
self.__dict__[k], batch.__dict__[k]])
elif isinstance(batch.__dict__[k], list):
self.__dict__[k] += batch.__dict__[k]
else:
s = 'No support for append with type' \
+ str(type(batch.__dict__[k])) \
+ 'in class Batch.'
raise TypeError(s)
def __len__(self) -> int:
"""Return len(self)."""
return min([
len(self.__dict__[k]) for k in self.__dict__
if k != '_meta' and self.__dict__[k] is not None])
def split(self, size: Optional[int] = None,
shuffle: bool = True) -> Iterator['Batch']:
"""Split whole data into multiple small batch.
:param int size: if it is ``None``, it does not split the data batch;
otherwise it will divide the data batch with the given size.
Default to ``None``.
:param bool shuffle: randomly shuffle the entire data batch if it is
``True``, otherwise remain in the same. Default to ``True``.
"""
length = len(self)
if size is None:
size = length
temp = 0
if shuffle:
index = np.random.permutation(length)
else:
index = np.arange(length)
while temp < length:
yield self[index[temp:temp + size]]
temp += size