在dask数据帧中，可以按groupby键不同的列对分组（由groupby api获取）数据帧进行排序 .
def func1(grouped_df):
grouped_df=grouped_df.sort_values(by=[“col2”])
….
…
return …
ddf.groupby（“COL1”） . 申请（FUNC1）.compute（）
在我的情况下失败，出现以下错误：
Traceback (most recent call last):
File "", line 4, in
File "/user/agent/miniconda3/envs/dask-distributed/lib/python3.6/site-packages/dask/base.py", line 135, in compute
(result,) = compute(self, traverse=False, **kwargs)
File "/user/agent/miniconda3/envs/dask-distributed/lib/python3.6/site-packages/dask/base.py", line 333, in compute
results = get(dsk, keys, **kwargs)
File "/user/agent/miniconda3/envs/dask-distributed/lib/python3.6/site-packages/distributed/client.py", line 1999, in get
results = self.gather(packed, asynchronous=asynchronous)
File "/user/agent/miniconda3/envs/dask-distributed/lib/python3.6/site-packages/distributed/client.py", line 1437, in gather
asynchronous=asynchronous)
File "/user/agent/miniconda3/envs/dask-distributed/lib/python3.6/site-packages/distributed/client.py", line 592, in sync
return sync(self.loop, func, *args, **kwargs)
File "/user/agent/miniconda3/envs/dask-distributed/lib/python3.6/site-packages/distributed/utils.py", line 254, in sync
six.reraise(*error[0])
File "/user/agent/miniconda3/envs/dask-distributed/lib/python3.6/site-packages/six.py", line 693, in reraise
raise value
File "/user/agent/miniconda3/envs/dask-distributed/lib/python3.6/site-packages/distributed/utils.py", line 238, in f
result[0] = yield make_coro()
File "/user/agent/miniconda3/envs/dask-distributed/lib/python3.6/site-packages/tornado/gen.py", line 1055, in run
value = future.result()
File "/user/agent/miniconda3/envs/dask-distributed/lib/python3.6/site-packages/tornado/concurrent.py", line 238, in result
raise_exc_info(self._exc_info)
File "", line 4, in raise_exc_info
File "/user/agent/miniconda3/envs/dask-distributed/lib/python3.6/site-packages/tornado/gen.py", line 1063, in run
yielded = self.gen.throw(*exc_info)
File "/user/agent/miniconda3/envs/dask-distributed/lib/python3.6/site-packages/distributed/client.py", line 1315, in _gather
traceback)
File "/user/agent/miniconda3/envs/dask-distributed/lib/python3.6/site-packages/six.py", line 692, in reraise
raise value.with_traceback(tb)
File "/user/agent/miniconda3/envs/dask-distributed/lib/python3.6/site-packages/dask/dataframe/core.py", line 3236, in apply_and_enforce
df = func(*args, **kwargs)
File "/user/agent/miniconda3/envs/dask-distributed/lib/python3.6/site-packages/dask/dataframe/groupby.py", line 147, in _groupby_slice_apply
return g.apply(func)
File "/user/agent/miniconda3/envs/dask-distributed/lib/python3.6/site-packages/pandas/core/groupby.py", line 805, in apply
return self._python_apply_general(f)
File "/user/agent/miniconda3/envs/dask-distributed/lib/python3.6/site-packages/pandas/core/groupby.py", line 809, in _python_apply_general
self.axis)
File "/user/agent/miniconda3/envs/dask-distributed/lib/python3.6/site-packages/pandas/core/groupby.py", line 1969, in apply
res = f(group)
File "", line 5, in main_func3
File "/user/agent/miniconda3/envs/dask-distributed/lib/python3.6/site-packages/pandas/core/series.py", line 623, in __getitem__
result = self.index.get_value(self, key)
File "/user/agent/miniconda3/envs/dask-distributed/lib/python3.6/site-packages/pandas/core/indexes/base.py", line 2560, in get_value
tz=getattr(series.dtype, 'tz', None))
File "pandas/_libs/index.pyx", line 83, in pandas._libs.index.IndexEngine.get_value
File "pandas/_libs/index.pyx", line 91, in pandas._libs.index.IndexEngine.get_value
File "pandas/_libs/index.pyx", line 139, in pandas._libs.index.IndexEngine.get_loc
File "pandas/_libs/hashtable_class_helper.pxi", line 811, in pandas._libs.hashtable.Int64HashTable.get_item
File "pandas/_libs/hashtable_class_helper.pxi", line 817, in pandas._libs.hashtable.Int64HashTable.get_item
KeyError: 0