将RPy2 ListVector转换为Python字典

Question

相当于R中命名列表的自然Python是一个dict,但RPy2为您提供了一个ListVector对象.

import rpy2.robjects as robjects

a = robjects.r('list(foo="barbat", fizz=123)')

此时,a是ListVector对象.

<ListVector - Python:0x108f92a28 / R:0x7febcba86ff0>
[StrVector, FloatVector]
  foo: <class 'rpy2.robjects.vectors.StrVector'>
  <StrVector - Python:0x108f92638 / R:0x7febce0ae0d8>
[str]
  fizz: <class 'rpy2.robjects.vectors.FloatVector'>
  <FloatVector - Python:0x10ac38fc8 / R:0x7febce0ae108>
[123.000000]

我想要的是我可以像普通的Python字典那样对待的东西.我的临时黑客是这样的:

def as_dict(vector):
    """Convert an RPy2 ListVector to a Python dict"""
    result = {}
    for i, name in enumerate(vector.names):
        if isinstance(vector[i], robjects.ListVector):
            result[name] = as_dict(vector[i])
        elif len(vector[i]) == 1:
            result[name] = vector[i][0]
        else:
            result[name] = vector[i]
    return result

as_dict(a)
{'foo': 'barbat', 'fizz': 123.0}

b = robjects.r('list(foo=list(bar=1, bat=c("one","two")), fizz=c(123,345))')
as_dict(b)
{'fizz': <FloatVector - Python:0x108f7e950 / R:0x7febcba86b90>
 [123.000000, 345.000000],
 'foo': {'bar': 1.0, 'bat': <StrVector - Python:0x108f7edd0 / R:0x7febcba86ea0>
  [str, str]}}

所以,问题是......在我应该使用的RPy2中是否有更好的方法或内容？

Answer 1

我认为将ar vector变为a dictionary不必如此涉及,如何:

In [290]:

dict(zip(a.names, list(a)))
Out[290]:
{'fizz': <FloatVector - Python:0x08AD50A8 / R:0x10A67DE8>
[123.000000],
 'foo': <StrVector - Python:0x08AD5030 / R:0x10B72458>
['barbat']}
In [291]:

dict(zip(a.names, map(list,list(a))))
Out[291]:
{'fizz': [123.0], 'foo': ['barbat']}

当然,如果你不介意使用pandas,那就更容易了.结果将numpy.array取而代之list,但在大多数情况下都可以:

In [294]:

import pandas.rpy.common as com
com.convert_robj(a)
Out[294]:
{'fizz': [123.0], 'foo': array(['barbat'], dtype=object)}

Answer 2

简单的R列表到Python字典:

>>> import rpy2.robjects as robjects
>>> a = robjects.r('list(foo="barbat", fizz=123)')
>>> d = { key : a.rx2(key)[0] for key in a.names }
>>> d
{'foo': 'barbat', 'fizz': 123.0}

使用R RJSONIO JSON序列化/反序列化的任意R对象到Python对象

在R服务器上:install.packages("RJSONIO",dependencies = TRUE)

>>> ro.r("library(RJSONIO)")
<StrVector - Python:0x300b8c0 / R:0x3fbccb0>
[str, str, str, ..., str, str, str]
>>> import rpy2.robjects as robjects
>>> rjson = robjects.r(' toJSON( list(foo="barbat", fizz=123, lst=list(33,"bb")) )  ')
>>> pyobj = json.loads( rjson[0] )
>>> pyobj
{u'lst': [33, u'bb'], u'foo': u'barbat', u'fizz': 123}
>>> pyobj['lst']
[33, u'bb']
>>> pyobj['lst'][0]
33
>>> pyobj['lst'][1]
u'bb'
>>> rjson = robjects.r(' toJSON( list(foo="barbat", fizz=123, lst=list( key1=33,key2="bb")) )  ')
>>> pyobj = json.loads( rjson[0] )
>>> pyobj
{u'lst': {u'key2': u'bb', u'key1': 33}, u'foo': u'barbat', u'fizz': 123}

Answer 3

您还可以执行以下操作：

在

dict(a.items())

出去

{'foo': R object with classes: ('character',) mapped to:
 ['barbat'], 'fizz': R object with classes: ('numeric',) mapped to:
 [123.000000]}

Answer 4

对于不同的rpy2向量类型的深度嵌套结构，我也遇到相同的问题。我在stackoverflow的任何地方都找不到直接的答案，所以这是我的解决方案。使用CT Zhu的答案，我想到了以下代码，将完整的结构递归转换为python类型。

from rpy2.robjects.vectors import DataFrame, FloatVector, IntVector, StrVector, ListVector
import numpy
from collections import OrderedDict

def recurList(data):
    rDictTypes = [ DataFrame,ListVector]
    rArrayTypes = [FloatVector,IntVector]
    rListTypes=[StrVector]
    if type(data) in rDictTypes:
        return OrderedDict(zip(data.names, [recurList(elt) for elt in data]))
    elif type(data) in rListTypes:
        return [recurList(elt) for elt in data]
    elif type(data) in rArrayTypes:
        return numpy.array(data)
    else:
        if hasattr(data, "rclass"): # An unsupported r class
            raise KeyError('Could not proceed, type {} is not defined'.format(type(data)))
        else:
            return data # We reached the end of recursion