---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
<ipython-input-140-d5c9ce8cbf4b> in <module>
----> 1 df['S0'].astype(int)
~/anaconda3/lib/python3.7/site-packages/pandas/core/generic.py in astype(self, dtype, copy, errors, **kwargs)
5880 # else, only a single dtype is given
5881 new_data = self._data.astype(
-> 5882 dtype=dtype, copy=copy, errors=errors, **kwargs
5883 )
5884 return self._constructor(new_data).__finalize__(self)
~/anaconda3/lib/python3.7/site-packages/pandas/core/internals/managers.py in astype(self, dtype, **kwargs)
579
580 def astype(self, dtype, **kwargs):
--> 581 return self.apply("astype", dtype=dtype, **kwargs)
582
583 def convert(self, **kwargs):
~/anaconda3/lib/python3.7/site-packages/pandas/core/internals/managers.py in apply(self, f, axes, filter, do_integrity_check, consolidate, **kwargs)
436 kwargs[k] = obj.reindex(b_items, axis=axis, copy=align_copy)
437
--> 438 applied = getattr(b, f)(**kwargs)
439 result_blocks = _extend_blocks(applied, result_blocks)
440
~/anaconda3/lib/python3.7/site-packages/pandas/core/internals/blocks.py in astype(self, dtype, copy, errors, values, **kwargs)
557
558 def astype(self, dtype, copy=False, errors="raise", values=None, **kwargs):
--> 559 return self._astype(dtype, copy=copy, errors=errors, values=values, **kwargs)
560
561 def _astype(self, dtype, copy=False, errors="raise", values=None, **kwargs):
~/anaconda3/lib/python3.7/site-packages/pandas/core/internals/blocks.py in _astype(self, dtype, copy, errors, values, **kwargs)
641 # _astype_nansafe works fine with 1-d only
642 vals1d = values.ravel()
--> 643 values = astype_nansafe(vals1d, dtype, copy=True, **kwargs)
644
645 # TODO(extension)
~/anaconda3/lib/python3.7/site-packages/pandas/core/dtypes/cast.py in astype_nansafe(arr, dtype, copy, skipna)
705 # work around NumPy brokenness, #1987
706 if np.issubdtype(dtype.type, np.integer):
--> 707 return lib.astype_intsafe(arr.ravel(), dtype).reshape(arr.shape)
708
709 # if we have a datetime/timedelta array of objects
pandas/_libs/lib.pyx in pandas._libs.lib.astype_intsafe()
ValueError: invalid literal for int() with base 10: 'neg'