Question

你好，我正在做一个关于prolog的项目，并且仍然掌握着这门语言。我目前有一个列表列表，其中子列表有坐标。

我的目的是选择具有特定坐标X的子列表，然后将该列表从第一个元素切割为X.（只有一个列表）

我认为首先问题是选择带成员的子列表。所以我试着这么做。

sublist([],_, []).
sublist([H|R],Pos, [H|Aux]) :-
    member(Pos,H), !,
    sublist(R,Pos, Aux).
sublist([H|R],Pos, Aux) :-
    sublist(R,Pos,Aux).

这不起作用：

?- sublist([[(1,2),(1,3),(3,5)],[(1,5),(1,2)]], (1,5), X).
X = [].

第一阶段我想要的是：

?- sublist([[(1,2),(1,3),(3,5)],[(1,5),(1,2)]], (1,5), X).
X = [(1,5),(1,2)].

（之后，当我选择了子列表时，我计划做一个类似的事情，我将元素添加到空列表中，直到元素等于X）。

最终结果将是：

?- sublist([[(1,2),(1,3),(3,5)],[(1,5),(1,2)]], (1,5), X).
X = [(1,5)].

我做错了什么？我还在学习Prolog的思考，所以我为明显的逻辑错误道歉。

Answer 1

如果我理解你的问题：

Traceback (most recent call last):
  File "C:\Users\tlsdy\AppData\Local\Programs\Python\Python36\lib\site-packages\pandas\core\indexes\base.py", line 2525, in get_loc
    return self._engine.get_loc(key)
  File "pandas\_libs\index.pyx", line 117, in pandas._libs.index.IndexEngine.get_loc
  File "pandas\_libs\index.pyx", line 139, in pandas._libs.index.IndexEngine.get_loc
  File "pandas\_libs\hashtable_class_helper.pxi", line 1265, in pandas._libs.hashtable.PyObjectHashTable.get_item
  File "pandas\_libs\hashtable_class_helper.pxi", line 1273, in pandas._libs.hashtable.PyObjectHashTable.get_item
KeyError: '(df["Unnamed: 13"] == "3") & (df["Unnamed: 15"] == "")'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "D:/python_project_ab/amazon/property.py", line 201, in <module>
    print(df[find_key_and_val])
  File "C:\Users\tlsdy\AppData\Local\Programs\Python\Python36\lib\site-packages\pandas\core\frame.py", line 2139, in __getitem__
    return self._getitem_column(key)
  File "C:\Users\tlsdy\AppData\Local\Programs\Python\Python36\lib\site-packages\pandas\core\frame.py", line 2146, in _getitem_column
    return self._get_item_cache(key)
  File "C:\Users\tlsdy\AppData\Local\Programs\Python\Python36\lib\site-packages\pandas\core\generic.py", line 1842, in _get_item_cache
    values = self._data.get(item)
  File "C:\Users\tlsdy\AppData\Local\Programs\Python\Python36\lib\site-packages\pandas\core\internals.py", line 3843, in get
    loc = self.items.get_loc(item)
  File "C:\Users\tlsdy\AppData\Local\Programs\Python\Python36\lib\site-packages\pandas\core\indexes\base.py", line 2527, in get_loc
    return self._engine.get_loc(self._maybe_cast_indexer(key))
  File "pandas\_libs\index.pyx", line 117, in pandas._libs.index.IndexEngine.get_loc
  File "pandas\_libs\index.pyx", line 139, in pandas._libs.index.IndexEngine.get_loc
  File "pandas\_libs\hashtable_class_helper.pxi", line 1265, in pandas._libs.hashtable.PyObjectHashTable.get_item
  File "pandas\_libs\hashtable_class_helper.pxi", line 1273, in pandas._libs.hashtable.PyObjectHashTable.get_item
KeyError: '(df["Unnamed: 13"] == "3") & (df["Unnamed: 15"] == "")'

（sublist(L, Elem, M) :- member(M, L), member(Elem, M).包含一个列表L，其中包含和元素M）

给出了结果：

Elem

Swi-Prolog从列表列表中选择列表

1 个答案: