Closed
Description
If we try and quantile a DataFrame with string entries which are not convertible, there is a ValueError. Should this behave like mean (and ignore these entries)? (taken from this StackOverflow question).
In [1]: df = DataFrame({'col1':['A','A','B','B'], 'col2':[1,2,3,4]})
In [2]: df
Out[2]:
col1 col2
0 A 1
1 A 2
2 B 3
3 B 4
In [3]: g = df.groupby('col1')
In [4]: g.mean()
Out[4]:
col2
col1
A 1.5
B 3.5
In [5]: g.quantile()
---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
/home/andy/<ipython-input-70-8b0757805794> in <module>()
----> 1 g.quantile()
/usr/lib/pymodules/python2.7/pandas/core/groupby.pyc in wrapper(*args, **kwargs)
258 return self.apply(curried_with_axis)
259 except Exception:
--> 260 return self.apply(curried)
261
262 return wrapper
/usr/lib/pymodules/python2.7/pandas/core/groupby.pyc in apply(self, func, *args, **kwargs)
319 func = _intercept_function(func)
320 f = lambda g: func(g, *args, **kwargs)
--> 321 return self._python_apply_general(f)
322
323 def _python_apply_general(self, f):
/usr/lib/pymodules/python2.7/pandas/core/groupby.pyc in _python_apply_general(self, f)
322
323 def _python_apply_general(self, f):
--> 324 keys, values, mutated = self.grouper.apply(f, self.obj, self.axis)
325
326 return self._wrap_applied_output(keys, values,
/usr/lib/pymodules/python2.7/pandas/core/groupby.pyc in apply(self, f, data, axis, keep_internal)
594 # group might be modified
595 group_axes = _get_axes(group)
--> 596 res = f(group)
597 if not _is_indexed_like(res, group_axes):
598 mutated = True
/usr/lib/pymodules/python2.7/pandas/core/groupby.pyc in <lambda>(g)
318 """
319 func = _intercept_function(func)
--> 320 f = lambda g: func(g, *args, **kwargs)
321 return self._python_apply_general(f)
322
/usr/lib/pymodules/python2.7/pandas/core/groupby.pyc in curried(x)
253
254 def curried(x):
--> 255 return f(x, *args, **kwargs)
256
257 try:
/usr/lib/pymodules/python2.7/pandas/core/frame.pyc in quantile(self, q, axis)
4946 return _quantile(arr, per)
4947
-> 4948 return self.apply(f, axis=axis)
4949
4950 def clip(self, upper=None, lower=None):
/usr/lib/pymodules/python2.7/pandas/core/frame.pyc in apply(self, func, axis, broadcast, raw, args, **kwds)
4079 return self._apply_raw(f, axis)
4080 else:
-> 4081 return self._apply_standard(f, axis)
4082 else:
4083 return self._apply_broadcast(f, axis)
/usr/lib/pymodules/python2.7/pandas/core/frame.pyc in _apply_standard(self, func, axis, ignore_failures)
4154 # no k defined yet
4155 pass
-> 4156 raise e
4157
4158 if len(results) > 0 and _is_sequence(results[0]):
ValueError: ('could not convert string to float: A', u'occurred at index col1')