Feature/pandas api isin

docs/user-guide/advanced/Pandas_API.ipynb

@@ -3014,6 +3014,105 @@
     "\n",
     "Example Table."
    ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "7f08eb84",
+   "metadata": {},
+   "source": [
+    "## Comparison\n",
+    "\n",
+    "### Table.isin()\n",
+    "\n",
+    "```\n",
+    "Table.apply(\n",
+    "    values\n",
+    ")\n",
+    "```\n",
+    "\n",
+    "Whether each element in the DataFrame is contained in values.\n",
+    "\n",
+    "**Parameters:**\n",
+    "\n",
+    "| Name             | Type                                | Description                                                                  | Default  |\n",
+    "| :--------------: | :---------------------------------: | :-------------------------------------------------------------------------- | :------: |\n",
+    "| values | Union[List, dict, Table, KeyedTable] | The result will only be true at a location if all the labels match. If values is a dict, the keys must be the column names, which must match. If values is a Table or KeyedTable, then both the index and column labels must match. |  None|\n",
+    "\n",
+    "\n",
+    "**Returns:**\n",
+    "\n",
+    "| Type                      | Description                                     |\n",
+    "| :-----------------------: | :---------------------------------------------- |\n",
+    "| Table | Boolean type Table/KeyedTable showing whether each element in the DataFrame is contained in values.|\n",
+    "\n",
+    "**Examples:**\n",
+    "\n",
+    "Example Table."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "f6e453c8",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "tab = kx.Table(data={'x': list(range(3)), 'y': [\"A\", \"B\", \"C\"]})"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "aadd23c1",
+   "metadata": {},
+   "source": [
+    "Find if element \"A\" or \"1\" is in the table:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "d41d40e0",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "tab.isin([\"A\", 1])"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "cff856fe",
+   "metadata": {},
+   "source": [
+    "Find if element \"A\" is in colum \"y\":"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "bccf59d9",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "tab.isin({\"y\": [\"A\"]})"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "ed704cce",
+   "metadata": {},
+   "source": [
+    "Find if element \"A\" is in the first position of \"y\" column:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "41840cc0",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "tab.isin(kx.Table(data={\"y\":[\"A\"]}))"
+   ]
   }
  ],
  "metadata": {

src/pykx/pandas_api/pandas_meta.py

@@ -210,6 +210,55 @@ def abs(self, numeric_only=False):
             tab = _get_numeric_only_subtable(self)
         return q.abs(tab)
 
+    @api_return
+    def isin(self, values):
+        tab = self
+        key_table = 'KeyedTable' in str(type(tab))
+        key_value = 'KeyedTable' in str(type(values))
+        n_rows = 0
+        false_dataframe_f = q("""{u:(cols x); 
+                            v:(count[u],count[x])#0b; 
+                            flip u!v}""")
+        if key_value and not key_table:
+            return false_dataframe_f(tab)
+        if key_table:
+            kcols = q.key(tab)
+            if key_value:
+                n_rows, tab = q("""{n_rows:max 0, count[x]-
+                                            count rows:(key y) inter key x; 
+                                            (n_rows;
+                                               x each rows)}""", tab, values)
+                values = q.value(values)
+            else:
+                tab = q.value(tab)
+        dic_value, is_tab = q("""{$[98h = type x;
+                                    (flip x; 1b);
+                                    (x; 0b)]}""", values)
+        if key_table and not key_value and is_tab:
+            ftable = false_dataframe_f(tab)
+        else:
+            ftable = q("""{ [table; values; is_tab; n_rows]
+                        flip (cols table)!
+                        {[col_name;tab;values;v_is_tab; n_rows]
+                            col: tab col_name;
+                            ltype: .Q.ty col;
+                            values: $[99h~type values; values col_name; values];
+                            $[v_is_tab or ltype=" ";;
+                                    values@:where (lower ltype) = .Q.t abs type each values];
+                            $[0 = count values;
+                                        (n_rows + count[col])#0b;
+                                        $[v_is_tab;
+                                            $[any ltype = (" ";"C");~';=]
+                                            [mlen#col;mlen#values],
+                                                (n_rows + max 0,count[col]-
+                                                    mlen: min count[values],
+                                                        count[col])#0b;
+                                            any $[any ltype = (" ";"C");~/:\:;=\:][values;col]
+                                            ]
+                                ]}[;table;values;is_tab; n_rows]
+                        each cols table}""", tab, dic_value, is_tab, n_rows)
+        return ftable.set_index(kcols) if key_table else ftable
+
     @convert_result
     def all(self, axis=0, bool_only=False, skipna=True):
         res, cols = preparse_computations(self, axis, skipna, bool_only=bool_only)

tests/test_pandas_api.py

@@ -2029,3 +2029,27 @@ def test_keyed_loc_fixes(q):
         mkt[['k1', 'y']]
     with pytest.raises(KeyError):
         mkt['k1']
+
+def test_pandas_isin(kx):
+    tab = kx.q("""([] k1: 0n 1. 0n 2. 0n;
+                      k2: ("A";" ";"B";" ";"A");
+                      k3: (`a;1.;`c;5;`d))""")
+    keyed_tab = kx.q("""([`a`b`c`d`e]
+                        k1: 0n 1. 0n 2. 0n;
+                        k2: ("A";" ";"B";" ";"A");
+                        k3: (`a;1.;`c;5;`d))""")
+
+    list_value = kx.q('(`a;1.;"A")')
+    dict_value = {"k1": [1., 2., 3.]}
+    tab_value = kx.q('([] k1: 1. 2. 3.; k2: ("A";"B";"C"))')
+    keyed_tab_value = kx.q('([`a`b] k1: 1. 2.; k2: ("A";"B"))')
+
+    assert tab.isin(list_value).pd().equals(tab.pd().isin(list_value.py()))
+    assert tab.isin(dict_value).pd().equals(tab.pd().isin(dict_value))
+    assert tab.isin(tab_value).pd().equals(tab.pd().isin(tab_value.pd()))
+    assert tab.isin(keyed_tab_value).pd().equals(tab.pd().isin(keyed_tab_value))
+    assert keyed_tab.isin(list_value).pd().equals(keyed_tab.pd().isin(list_value.py()))
+    assert keyed_tab.isin(dict_value).pd().equals(keyed_tab.pd().isin(dict_value))
+    assert keyed_tab.isin(keyed_tab_value).pd().equals(keyed_tab.pd().isin(keyed_tab_value.pd()))
+    assert keyed_tab.isin(tab_value).pd().equals(keyed_tab.pd().isin(tab_value))
+