wip

dios/dios.py

@@ -7,6 +7,7 @@ from collections import OrderedDict
 from itertools import islice
 import operator as op
 import functools
+from pandas.core.indexing import need_slice
 
 # _listlike = (list, set)
 
@@ -44,20 +45,69 @@ def item_from_zerodim(key):
 
 class _LocIndexer:
 
-    def __init__(self, _data):
-        self._data = _data
+    def __init__(self, _dios):
+        self._dios = _dios
+        # short handles
+        self._data = _dios._data
+        self._check_keys = _dios._check_keys
 
     def __getitem__(self, key):
-        rkey = None
-        ckey = None
-
-        # unpack tuple
+        # if we have a tuple, we have rows and columns
+        # if not we have only rows
         if isinstance(key, tuple):
             rkey, ckey, *fail = key
             if fail:
                 raise KeyError("To many indexers")
 
+            # prepare ckey
+            if is_iterator(ckey):
+                ckey = list(ckey)
+
+            # determine columns
+            if isinstance(ckey, str):
+                self._check_keys([ckey])
+                cols = [ckey]
+            elif isinstance(ckey, slice):
+                cols = self._col_slice_to_col_list(ckey)
+            elif is_list_like(ckey):
+                self._check_keys(ckey)
+                cols = ckey
+            else:
+                raise KeyError(f"Type {type(ckey)} is not supported to select columns.")
+        else:
+            cols = list(self._data.keys())
+            rkey = key
+
+        # prepare rkey
+        rkey = item_from_zerodim(rkey)
+        if is_iterator(rkey):
+            rkey = list(rkey)
 
+        # determine rows, these are mandatory
+        # slice, bool, list-like, label
+        if isinstance(rkey, slice):
+            # todo: validate slice ?
+            return self._slice(cols, rkey)
+
+    def _slice(self, keys, sl):
+        new = DictOfSeries()
+        for k in keys:
+            new[k] = self._data[k][sl]
+        return new
+
+    def _col_slice_to_col_list(self, rslice):
+        """ see here:
+        https://pandas.pydata.org/pandas-docs/stable/user_guide/indexing.html#indexing-slicing-with-labels
+        """
+        keys = list(self._data.keys)
+        try:
+            start = keys.index(rslice.start) if rslice.start is not None else None
+            stop = keys.index(rslice.stop) if rslice.stop is not None else None
+        except ValueError:
+            raise KeyError("The slice start label or the slice stop label is not present in the columns.")
+        if not is_number(rslice):
+            raise TypeError("The step parameter of the slice must be numeric.")
+        return keys[slice(start, stop, rslice.step)]
 
 
 class DictOfSeries:
@@ -103,7 +153,11 @@ class DictOfSeries:
         If 'iterable' contains any(!) label that does not exist
         a KeyError is raised
         """
+
+        # prepare
         key = item_from_zerodim(key)
+        if is_iterator(key):
+            key = list(key)
 
         # todo: allow any hashable obj, except stuff that fail: None/np.nan
         if isinstance(key, str):
@@ -146,6 +200,11 @@ class DictOfSeries:
         dios[iterable]
         """
 
+        # prepare
+        key = item_from_zerodim(key)
+        if is_iterator(key):
+            key = list(key)
+
         # determine action by keys
         if isinstance(key, str):
             if key not in self.columns:
@@ -247,11 +306,9 @@ class DictOfSeries:
         for k in keys:
             self._setitem(k, other[k], slicer)
 
-
     @property
     def loc(self):
-        return _LocIndexer(self._data)
-
+        return _LocIndexer(self)
 
     def __str__(self):
         return self.__repr__()
@@ -284,13 +341,13 @@ class DictOfSeries:
 
     @property
     def empty(self):
-        return all(c.empty for c in self._data)
+        return all(self._data[c].empty for c in self._data)
 
     def all(self):
-        return all(all(c) for c in self._data)
+        return all(all(self._data[c]) for c in self._data)
 
     def any(self):
-        return any(any(c) for c in self._data)
+        return any(any(self._data[c]) for c in self._data)
 
     def __len__(self):
         return len(self._data)
@@ -458,6 +515,9 @@ if __name__ == '__main__':
     dios2 = dios.copy()
 
     a = dios.loc[9]
+    df = pd.DataFrame([1,24,5,456,45], index=pd.date_range(periods=5, freq='1d', start='2000-01-01'))
+    a = df.loc["2000-01-02":]
+    print(a)
     exit(4)
 
     dios.columns = ['foo', 'bar']