Merge pull request #2 from maxhumber/easygather

Easygather

Author: maxhumber

CHANGELOG

@@ -1,3 +1,6 @@
+- 1.3b1
+    - NEW: `gather(beside=...)` argument!
+    - IMPROVED: `sample` errors are more explicit
 - 1.2
     - NEW: `cross` join verb!
     - NEW: `join(..., postfix=("_lhs, "_rhs"))` argument

TODO

@@ -1,3 +1,4 @@
+- remove summarize
 - explode, collapse verbs
 - more research into `.assign` mutate(..., vectorized=True)?
 - datasets
@@ -8,4 +9,4 @@
 - hide/protect/private
 - 10 minutes tutorial
 - cheatsheet (pandas/dplyr/tidyr)
-- anaconda
+- anaconda?

redframes/core.py

@@ -819,50 +819,88 @@ def filter(self, func: Func) -> DataFrame:
     def gather(
         self,
         columns: Columns | None = None,
+        beside: LazyColumns | None = None,
         into: tuple[Column, Column] = ("variable", "value"),
     ):
-        """Lengthen data, increase rows, decrease columns (opposite of `spread`)
+        """Lengthen data by increasing rows and decreasing columns (opposite of `spread`)
 
         pandas: `melt`
         tidyverse: `gather`, `pivot_longer`
 
         Examples:
 
         ```python
-        df = rf.DataFrame({"foo": [1, 2], "bar": [3, 4], "baz": [4, 5]})
+        df = rf.DataFrame({
+            "foo": [1, 2, 1, 2],
+            "bar": ["A", "B", "C", "D"],
+            "baz": ["!", "@", "#", "$"],
+            "jaz": range(4)
+        })
         ```
-        |   foo |   bar |   baz |
-        |------:|------:|------:|
-        |     1 |     3 |     4 |
-        |     2 |     4 |     5 |
+        |   foo | bar   | baz   |   jaz |
+        |------:|:------|:------|------:|
+        |     1 | A     | !     |     0 |
+        |     2 | B     | @     |     1 |
+        |     1 | C     | #     |     2 |
+        |     2 | D     | $     |     3 |
 
         All columns:
 
         ```python
         df.gather()
         ```
-        | variable   |   value |
-        |:-----------|--------:|
-        | foo        |       1 |
-        | foo        |       2 |
-        | bar        |       3 |
-        | bar        |       4 |
-        | baz        |       4 |
-        | baz        |       5 |
+        | variable   | value   |
+        |:-----------|:--------|
+        | foo        | 1       |
+        | foo        | 2       |
+        | foo        | 1       |
+        | foo        | 2       |
+        | bar        | A       |
+        | bar        | B       |
+        | bar        | C       |
+        | bar        | D       |
+        | baz        | !       |
+        | baz        | @       |
+        | baz        | #       |
+        | baz        | $       |
+        | jaz        | 0       |
+        | jaz        | 1       |
+        | jaz        | 2       |
+        | jaz        | 3       |
 
         Multiple columns:
 
         ```python
         df.gather(["foo", "bar"], into=("var", "val"))
         ```
-        |   baz | var   |   val |
-        |------:|:------|------:|
-        |     4 | foo   |     1 |
-        |     5 | foo   |     2 |
-        |     4 | bar   |     3 |
-        |     5 | bar   |     4 |
+        | baz   |   jaz | var   | val   |
+        |:------|------:|:------|:------|
+        | !     |     0 | foo   | 1     |
+        | @     |     1 | foo   | 2     |
+        | #     |     2 | foo   | 1     |
+        | $     |     3 | foo   | 2     |
+        | !     |     0 | bar   | A     |
+        | @     |     1 | bar   | B     |
+        | #     |     2 | bar   | C     |
+        | $     |     3 | bar   | D     |
+
+        All columns except:
+
+        ```python
+        df.gather(beside=["foo", "bar"])
+        ```
+        |   foo | bar   | variable   | value   |
+        |------:|:------|:-----------|:--------|
+        |     1 | A     | baz        | !       |
+        |     2 | B     | baz        | @       |
+        |     1 | C     | baz        | #       |
+        |     2 | D     | baz        | $       |
+        |     1 | A     | jaz        | 0       |
+        |     2 | B     | jaz        | 1       |
+        |     1 | C     | jaz        | 2       |
+        |     2 | D     | jaz        | 3       |
         """
-        return _wrap(gather(self._data, columns, into))
+        return _wrap(gather(self._data, columns, beside, into))
 
     def group(self, by: LazyColumns) -> GroupedFrame:
         """Create a GroupedFrame overwhich split-apply-combine operations can be applied
@@ -1324,7 +1362,7 @@ def split(
         return _wrap(split(self._data, column, into, sep, drop))
 
     def spread(self, column: Column, using: Column) -> DataFrame:
-        """Widen data, increase columns, decreas rows (opposite of `gather`)
+        """Widen data by increasing columns and decreasing rows (opposite of `gather`)
 
         pandas: `pivot_table`
         tidyverse: `spread`, `pivot_wider`

redframes/verbs/gather.py

@@ -3,31 +3,41 @@
 import pandas as pd
 
 from ..checks import _check_type
-from ..types import Column, Columns, PandasDataFrame
+from ..types import Column, Columns, LazyColumns, PandasDataFrame
 
 
 def gather(
     df: PandasDataFrame,
     columns: Columns | None = None,
+    beside: LazyColumns | None = None,
     into: tuple[Column, Column] = ("variable", "value"),
 ) -> PandasDataFrame:
     _check_type(columns, {list, None})
+    _check_type(beside, {str, list, None})
     _check_type(into, tuple)
-    if not (isinstance(into, tuple) and len(into) == 2):
+    if not (isinstance(into, tuple) and (len(into) == 2)):
         raise TypeError("must be tuple[str, str]")
     if into[0] == into[1]:
         raise TypeError("must be unique")
-    if into[0] in df.columns:
+    if (into[0] in df.columns) or (into[1] in df.columns):
         raise TypeError("must not be an existing column key")
-    if into[1] in df.columns:
-        raise TypeError("must not be an existing column key")
-    if columns == None:
-        columns = list(df.columns)
-    index = [col for col in df.columns if col not in columns]  # type: ignore
+    if (columns != None) and (beside != None):
+        raise ValueError("columns OR beside must be None")
+    if (columns == None) and (beside == None):
+        id_vars = []
+        value_vars = list(df.columns)
+    if isinstance(beside, str):
+        beside = [beside]
+    if isinstance(beside, list):
+        id_vars = beside
+        value_vars = [col for col in df.columns if col not in id_vars]
+    if isinstance(columns, list):
+        id_vars = [col for col in df.columns if col not in columns]
+        value_vars = columns
     df = pd.melt(
         df,
-        id_vars=index,
-        value_vars=columns,
+        id_vars=id_vars,
+        value_vars=value_vars,
         var_name=into[0],
         value_name=into[1],
     )

redframes/verbs/sample.py

@@ -10,11 +10,11 @@ def sample(
     _check_type(rows, {int, float})
     if rows >= 1:
         if isinstance(rows, float):
-            raise ValueError("rows (int) must be >= 1")
+            raise ValueError("must be int if > 1")
         df = df.sample(rows, random_state=seed)
     elif 0 < rows < 1:
         df = df.sample(frac=rows, random_state=seed)
     else:
-        raise ValueError("rows (float) must be (0, 1)")
+        raise ValueError("must be > 0")
     df = df.reset_index(drop=True)
     return df

redframes/version.py

@@ -1 +1 @@
-__version__ = "1.2"
+__version__ = "1.3b1"

tests/test_docstrings.py

@@ -218,24 +218,76 @@ def test_filter(self):
         self.assertEqual(result3, expected3)
 
     def test_gather(self):
-        df = rf.DataFrame({"foo": [1, 2], "bar": [3, 4], "baz": [4, 5]})
+        df = rf.DataFrame(
+            {
+                "foo": [1, 2, 1, 2],
+                "bar": ["A", "B", "C", "D"],
+                "baz": ["!", "@", "#", "$"],
+                "jaz": range(4),
+            }
+        )
         result1 = df.gather()
         result2 = df.gather(["foo", "bar"], into=("var", "val"))
+        result3 = df.gather(beside=["foo", "bar"])
         expected1 = rf.DataFrame(
             {
-                "variable": ["foo", "foo", "bar", "bar", "baz", "baz"],
-                "value": [1, 2, 3, 4, 4, 5],
+                "variable": [
+                    "foo",
+                    "foo",
+                    "foo",
+                    "foo",
+                    "bar",
+                    "bar",
+                    "bar",
+                    "bar",
+                    "baz",
+                    "baz",
+                    "baz",
+                    "baz",
+                    "jaz",
+                    "jaz",
+                    "jaz",
+                    "jaz",
+                ],
+                "value": [
+                    1,
+                    2,
+                    1,
+                    2,
+                    "A",
+                    "B",
+                    "C",
+                    "D",
+                    "!",
+                    "@",
+                    "#",
+                    "$",
+                    0,
+                    1,
+                    2,
+                    3,
+                ],
             }
         )
         expected2 = rf.DataFrame(
             {
-                "baz": [4, 5, 4, 5],
-                "var": ["foo", "foo", "bar", "bar"],
-                "val": [1, 2, 3, 4],
+                "baz": ["!", "@", "#", "$", "!", "@", "#", "$"],
+                "jaz": [0, 1, 2, 3, 0, 1, 2, 3],
+                "var": ["foo", "foo", "foo", "foo", "bar", "bar", "bar", "bar"],
+                "val": [1, 2, 1, 2, "A", "B", "C", "D"],
+            }
+        )
+        expected3 = rf.DataFrame(
+            {
+                "foo": [1, 2, 1, 2, 1, 2, 1, 2],
+                "bar": ["A", "B", "C", "D", "A", "B", "C", "D"],
+                "variable": ["baz", "baz", "baz", "baz", "jaz", "jaz", "jaz", "jaz"],
+                "value": ["!", "@", "#", "$", 0, 1, 2, 3],
             }
         )
         self.assertEqual(result1, expected1)
         self.assertEqual(result2, expected2)
+        self.assertEqual(result3, expected3)
 
     def test_group(self):
         df = rf.DataFrame(

tests/test_ladybugs.py

@@ -25,3 +25,13 @@ def test_comine_overwrite_and_drop_other(self):
         result = df.combine(["foo", "bar"], into="foo", sep="-", drop=True)
         expected = rf.DataFrame({"foo": ["1-1", "2-2", "3-3"]})
         self.assertEqual(result, expected)
+
+    def test_sample_float_1_point_0(self):
+        df = rf.DataFrame({"foo": range(100)})
+        with self.assertRaisesRegex(ValueError, "must be int if > 1"):
+            df.sample(1.0)
+
+    def test_sample_negative_1(self):
+        df = rf.DataFrame({"foo": range(100)})
+        with self.assertRaisesRegex(ValueError, "must be > 0"):
+            df.sample(-1)

tests/test_type_hints.py

@@ -156,10 +156,23 @@ def test_gather_bad_columns(self):
         with self.assertRaisesRegex(TypeError, "must be list | None"):
             self.df.gather(1)
 
+    def test_gather_bad_beside(self):
+        with self.assertRaisesRegex(TypeError, "must be str | list | None"):
+            self.df.gather(beside=1)
+
     def test_gather_bad_into_column(self):
         with self.assertRaisesRegex(TypeError, "must be tuple"):
             self.df.gather(["foo", "bar"], into=1)
 
+    def test_gather_bad_into_tuple(self):
+        # with self.assertRaisesRegex(TypeError, f'must be tuple[str, str]'):
+        #     self.df.gather(into=("one", "two", "three"))
+        pass
+
+    def test_gather_bad_both_not_none(self):
+        with self.assertRaisesRegex(ValueError, "columns OR beside must be None"):
+            self.df.gather(columns=["foo", "bar"], beside=["baz"])
+
     def test_group_bad_by_columns(self):
         with self.assertRaisesRegex(TypeError, "must be list | str"):
             self.df.group(1)