Closed
Description
In [4]: df = pd.DataFrame({'a': [1, 2, 3]})
In [5]: df.take(1)
...
~/scipy/pandas/pandas/core/indexes/range.py in take(self, indices, axis, allow_fill, fill_value, **kwargs)
433 ) -> Int64Index:
434 with rewrite_exception("Int64Index", type(self).__name__):
--> 435 return self._int64index.take(
436 indices,
437 axis=axis,
~/scipy/pandas/pandas/core/indexes/base.py in take(self, indices, axis, allow_fill, fill_value, **kwargs)
962 self._values, indices, allow_fill=allow_fill, fill_value=self._na_value
963 )
--> 964 return type(self)._simple_new(taken, name=self.name)
965
966 @final
~/scipy/pandas/pandas/core/indexes/base.py in _simple_new(cls, values, name)
611 Must be careful not to recurse.
612 """
--> 613 assert isinstance(values, np.ndarray), type(values)
614
615 result = object.__new__(cls)
AssertionError: <class 'numpy.int64'>
take requires an array-like for the indexer, but when passing a scalar you get a not very useful error message as above. We should raise a ValueError (or rather TypeError) instead with an informative message.
It actually comes from the Index take implementation:
In [9]: pd.Index([1, 2, 3]).take(1)
---------------------------------------------------------------------------
AssertionError Traceback (most recent call last)
<ipython-input-9-ce9f87ba8bd2> in <module>
----> 1 pd.Index([1, 2, 3]).take(1)
~/scipy/pandas/pandas/core/indexes/base.py in take(self, indices, axis, allow_fill, fill_value, **kwargs)
962 self._values, indices, allow_fill=allow_fill, fill_value=self._na_value
963 )
--> 964 return type(self)._simple_new(taken, name=self.name)
965
966 @final
~/scipy/pandas/pandas/core/indexes/base.py in _simple_new(cls, values, name)
611 Must be careful not to recurse.
612 """
--> 613 assert isinstance(values, np.ndarray), type(values)
614
615 result = object.__new__(cls)
AssertionError: <class 'numpy.int64'>