ValueError: buffer source array is read-only · Issue #11502 · pandas-dev/pandas (original) (raw)
After upgrading to 0.17 (anaconda 2.7 + OSX), I'm finding that some previously working code is failing with ValueError: buffer source array is read-only. Driver code is below. The issue is basically the series version of #10043. I think the problem is that the patch for #10043 (#10070) only fixed the take_2d templates, leaving the take_1d (Series) versions with the old behavior. Based on my naive understanding, it might be straightforward to extend #10070 for the 1D cases.
import pandas as pd
import numpy as np
array = np.arange(10)
array.setflags(write=False)
X = pd.Series(array)
key = 0
keys = [key]
X.iloc[keys]
# OK
X.loc[keys]
# Fail
X.ix[keys]
# Fail
X.iloc[key]
# OK
X.loc[key]
# OK
X.ix[key]
# OK
Stacktrace is below.
ValueError Traceback (most recent call last)
<ipython-input-53-928f0ea51c58> in <module>()
----> 1 X.loc[keys]
~/opt/lib/python2.7/site-packages/pandas/core/indexing.py in __getitem__(self, key)
1196 return self._getitem_tuple(key)
1197 else:
-> 1198 return self._getitem_axis(key, axis=0)
1199
1200 def _getitem_axis(self, key, axis=0):
~/opt/lib/python2.7/site-packages/pandas/core/indexing.py in _getitem_axis(self, key, axis)
1330 raise ValueError('Cannot index with multidimensional key')
1331
-> 1332 return self._getitem_iterable(key, axis=axis)
1333
1334 # nested tuple slicing
~/opt/lib/python2.7/site-packages/pandas/core/indexing.py in _getitem_iterable(self, key, axis)
973
974 try:
--> 975 result = self.obj.reindex_axis(keyarr, axis=axis, level=level)
976
977 # this is an error as we are trying to find
~/opt/lib/python2.7/site-packages/pandas/core/series.py in reindex_axis(self, labels, axis, **kwargs)
2276 if axis != 0:
2277 raise ValueError("cannot reindex series on non-zero axis!")
-> 2278 return self.reindex(index=labels, **kwargs)
2279
2280 def take(self, indices, axis=0, convert=True, is_copy=False):
~/opt/lib/python2.7/site-packages/pandas/core/series.py in reindex(self, index, **kwargs)
2257 @Appender(generic._shared_docs['reindex'] % _shared_doc_kwargs)
2258 def reindex(self, index=None, **kwargs):
-> 2259 return super(Series, self).reindex(index=index, **kwargs)
2260
2261 @Appender(generic._shared_docs['fillna'] % _shared_doc_kwargs)
~/opt/lib/python2.7/site-packages/pandas/core/generic.py in reindex(self, *args, **kwargs)
1846 # perform the reindex on the axes
1847 return self._reindex_axes(axes, level, limit, tolerance,
-> 1848 method, fill_value, copy).__finalize__(self)
1849
1850 def _reindex_axes(self, axes, level, limit, tolerance, method,
~/opt/lib/python2.7/site-packages/pandas/core/generic.py in _reindex_axes(self, axes, level, limit, tolerance, method, fill_value, copy)
1865 obj = obj._reindex_with_indexers(
1866 {axis: [new_index, indexer]},
-> 1867 fill_value=fill_value, copy=copy, allow_dups=False)
1868
1869 return obj
~/opt/lib/python2.7/site-packages/pandas/core/generic.py in _reindex_with_indexers(self, reindexers, fill_value, copy, allow_dups)
1957 fill_value=fill_value,
1958 allow_dups=allow_dups,
-> 1959 copy=copy)
1960
1961 if copy and new_data is self._data:
~/opt/lib/python2.7/site-packages/pandas/core/internals.py in reindex_indexer(self, new_axis, indexer, axis, fill_value, allow_dups, copy)
3397 if axis == 0:
3398 new_blocks = self._slice_take_blocks_ax0(
-> 3399 indexer, fill_tuple=(fill_value,))
3400 else:
3401 new_blocks = [blk.take_nd(indexer, axis=axis,
~/opt/lib/python2.7/site-packages/pandas/core/internals.py in _slice_take_blocks_ax0(self, slice_or_indexer, fill_tuple)
3438 return [blk.take_nd(slobj, axis=0,
3439 new_mgr_locs=slice(0, sllen),
-> 3440 fill_tuple=fill_tuple)]
3441
3442 if sl_type in ('slice', 'mask'):
~/opt/lib/python2.7/site-packages/pandas/core/internals.py in take_nd(self, indexer, axis, new_mgr_locs, fill_tuple)
933 fill_value = fill_tuple[0]
934 new_values = com.take_nd(values, indexer, axis=axis,
--> 935 allow_fill=True, fill_value=fill_value)
936
937 if new_mgr_locs is None:
~/opt/lib/python2.7/site-packages/pandas/core/common.py in take_nd(arr, indexer, axis, out, fill_value, mask_info, allow_fill)
782 axis=axis, mask_info=mask_info)
783 indexer = _ensure_int64(indexer)
--> 784 func(arr, indexer, out, fill_value)
785
786 if flip_order:
pandas/src/generated.pyx in pandas.algos.take_1d_int64_int64 (pandas/algos.c:87226)()
~/opt/lib/python2.7/site-packages/pandas/algos.so in View.MemoryView.memoryview_cwrapper (pandas/algos.c:176760)()
~/opt/lib/python2.7/site-packages/pandas/algos.so in View.MemoryView.memoryview.__cinit__ (pandas/algos.c:173129)()
ValueError: buffer source array is read-only