我有以下数据框my_df：
col_A col_B
---------------
John []
Mary ['A','B','C']
Ann ['B','C']
我要删除
col_B具有空列表的行。即我希望新数据框为：col_A col_B
---------------
Mary ['A','B','C']
Ann ['B','C']
以下是我的工作：
my_df[ len(my_df['col_B']) >0 ]
但是我遇到了以下错误：
KeyError Traceback (most recent call last)
/usr/local/lib/python3.4/dist-packages/pandas/indexes/base.py in get_loc(self, key, method, tolerance)
2133 try:
-> 2134 return self._engine.get_loc(key)
2135 except KeyError:
pandas/index.pyx in pandas.index.IndexEngine.get_loc (pandas/index.c:4164)()
pandas/index.pyx in pandas.index.IndexEngine.get_loc (pandas/index.c:4028)()
pandas/src/hashtable_class_helper.pxi in pandas.hashtable.PyObjectHashTable.get_item (pandas/hashtable.c:13166)()
pandas/src/hashtable_class_helper.pxi in pandas.hashtable.PyObjectHashTable.get_item (pandas/hashtable.c:13120)()
KeyError: True
During handling of the above exception, another exception occurred:
KeyError Traceback (most recent call last)
<ipython-input-27-75da0b0af6a1> in <module>()
----> 1 records_df_pair_count[ len(records_df_pair_count['stable_seq']) >0 ]
/usr/local/lib/python3.4/dist-packages/pandas/core/frame.py in __getitem__(self, key)
2057 return self._getitem_multilevel(key)
2058 else:
-> 2059 return self._getitem_column(key)
2060
2061 def _getitem_column(self, key):
/usr/local/lib/python3.4/dist-packages/pandas/core/frame.py in _getitem_column(self, key)
2064 # get column
2065 if self.columns.is_unique:
-> 2066 return self._get_item_cache(key)
2067
2068 # duplicate columns & possible reduce dimensionality
/usr/local/lib/python3.4/dist-packages/pandas/core/generic.py in _get_item_cache(self, item)
1384 res = cache.get(item)
1385 if res is None:
-> 1386 values = self._data.get(item)
1387 res = self._box_item_values(item, values)
1388 cache[item] = res
/usr/local/lib/python3.4/dist-packages/pandas/core/internals.py in get(self, item, fastpath)
3539
3540 if not isnull(item):
-> 3541 loc = self.items.get_loc(item)
3542 else:
3543 indexer = np.arange(len(self.items))[isnull(self.items)]
/usr/local/lib/python3.4/dist-packages/pandas/indexes/base.py in get_loc(self, key, method, tolerance)
2134 return self._engine.get_loc(key)
2135 except KeyError:
-> 2136 return self._engine.get_loc(self._maybe_cast_indexer(key))
2137
2138 indexer = self.get_indexer([key], method=method, tolerance=tolerance)
pandas/index.pyx in pandas.index.IndexEngine.get_loc (pandas/index.c:4164)()
pandas/index.pyx in pandas.index.IndexEngine.get_loc (pandas/index.c:4028)()
pandas/src/hashtable_class_helper.pxi in pandas.hashtable.PyObjectHashTable.get_item (pandas/hashtable.c:13166)()
pandas/src/hashtable_class_helper.pxi in pandas.hashtable.PyObjectHashTable.get_item (pandas/hashtable.c:13120)()
KeyError: True
知道我在这里做错了什么吗？谢谢！
最佳答案
另一种方法是：
my_df[my_df['col_b'].apply(lambda x: len(x)) > 0]
关于python-3.x - Pandas :筛选出包含空列表的列值，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/42964724/