Recursively convert rpy2 objects to nested Python data structures.

ri2py_recursive.py

#!/usr/bin/env python3

"""
Recursively convert rpy2 objects to nested Python data structures.
"""

import numpy as np
from rpy2.robjects import default_converter, globalenv, \
        NULL, numpy2ri, pandas2ri, ListVector, r

def scalarize(x):
    if not np.isscalar(x) and len(x) == 1:
        return np.asscalar(x)
    else:
        return x

converter = default_converter+numpy2ri.converter+pandas2ri.converter
def convert(ri):
    """
    Recursively convert rpy2 object to nested Python object.

    Objects containing R code (typeof(x) == 'language') are filtered out.
    Objects containing R lists with no string tags are converted to Python
    lists.
    """

    if isinstance(ri, ListVector):
        if ri.names == NULL:
            result = [convert(tmp[1]) for tmp in ri.items()]
        else:
            result = {}
            for name in ri.names:
                globalenv['tmp'] = ri.rx2(name)
                if r('typeof(tmp)')[0] != 'language':
                    result[name] = convert(ri.rx2(name))
        return result
    else:
        return scalarize(converter.ri2py(ri))