REF: make plotting less stateful (2) (#55850)

* REF: validate_sharex

* REF: make plotting less stateful (2)

* pylint ignore

* mypy fixup

Author: jbrockmendel

pandas/plotting/_matplotlib/boxplot.py

@@ -81,7 +81,6 @@ def __init__(self, data, return_type: str = "axes", **kwargs) -> None:
         # Do not call LinePlot.__init__ which may fill nan
         MPLPlot.__init__(self, data, **kwargs)  # pylint: disable=non-parent-init-called
 
-    def _args_adjust(self) -> None:
         if self.subplots:
             # Disable label ax sharing. Otherwise, all subplots shows last
             # column label

pandas/plotting/_matplotlib/core.py

@@ -25,6 +25,7 @@
 
 from pandas.core.dtypes.common import (
     is_any_real_numeric_dtype,
+    is_bool,
     is_float,
     is_float_dtype,
     is_hashable,
@@ -130,7 +131,7 @@ def __init__(
         kind=None,
         by: IndexLabel | None = None,
         subplots: bool | Sequence[Sequence[str]] = False,
-        sharex=None,
+        sharex: bool | None = None,
         sharey: bool = False,
         use_index: bool = True,
         figsize: tuple[float, float] | None = None,
@@ -191,17 +192,7 @@ def __init__(
 
         self.subplots = self._validate_subplots_kwarg(subplots)
 
-        if sharex is None:
-            # if by is defined, subplots are used and sharex should be False
-            if ax is None and by is None:
-                self.sharex = True
-            else:
-                # if we get an axis, the users should do the visibility
-                # setting...
-                self.sharex = False
-        else:
-            self.sharex = sharex
-
+        self.sharex = self._validate_sharex(sharex, ax, by)
         self.sharey = sharey
         self.figsize = figsize
         self.layout = layout
@@ -275,6 +266,20 @@ def __init__(
 
         self._validate_color_args()
 
+    @final
+    def _validate_sharex(self, sharex: bool | None, ax, by) -> bool:
+        if sharex is None:
+            # if by is defined, subplots are used and sharex should be False
+            if ax is None and by is None:  # pylint: disable=simplifiable-if-statement
+                sharex = True
+            else:
+                # if we get an axis, the users should do the visibility
+                # setting...
+                sharex = False
+        elif not is_bool(sharex):
+            raise TypeError("sharex must be a bool or None")
+        return bool(sharex)
+
     @final
     def _validate_subplots_kwarg(
         self, subplots: bool | Sequence[Sequence[str]]
@@ -454,7 +459,6 @@ def draw(self) -> None:
 
     @final
     def generate(self) -> None:
-        self._args_adjust()
         self._compute_plot_data()
         fig = self._setup_subplots()
         self._make_plot(fig)
@@ -466,10 +470,6 @@ def generate(self) -> None:
             self._post_plot_logic_common(ax, self.data)
             self._post_plot_logic(ax, self.data)
 
-    @abstractmethod
-    def _args_adjust(self) -> None:
-        pass
-
     @final
     def _has_plotted_object(self, ax: Axes) -> bool:
         """check whether ax has data"""
@@ -1326,9 +1326,6 @@ def _make_plot(self, fig: Figure):
             err_kwds["ecolor"] = scatter.get_facecolor()[0]
             ax.errorbar(data[x].values, data[y].values, linestyle="none", **err_kwds)
 
-    def _args_adjust(self) -> None:
-        pass
-
 
 class HexBinPlot(PlanePlot):
     @property
@@ -1361,9 +1358,6 @@ def _make_plot(self, fig: Figure) -> None:
     def _make_legend(self) -> None:
         pass
 
-    def _args_adjust(self) -> None:
-        pass
-
 
 class LinePlot(MPLPlot):
     _default_rot = 0
@@ -1529,9 +1523,6 @@ def _update_stacker(cls, ax: Axes, stacking_id, values) -> None:
         elif (values <= 0).all():
             ax._stacker_neg_prior[stacking_id] += values
 
-    def _args_adjust(self) -> None:
-        pass
-
     def _post_plot_logic(self, ax: Axes, data) -> None:
         from matplotlib.ticker import FixedLocator
 
@@ -1641,9 +1632,6 @@ def _plot(  # type: ignore[override]
         res = [rect]
         return res
 
-    def _args_adjust(self) -> None:
-        pass
-
     def _post_plot_logic(self, ax: Axes, data) -> None:
         LinePlot._post_plot_logic(self, ax, data)
 
@@ -1676,8 +1664,14 @@ def __init__(self, data, **kwargs) -> None:
         kwargs.setdefault("align", "center")
         self.tick_pos = np.arange(len(data))
 
-        self.bottom = kwargs.pop("bottom", 0)
-        self.left = kwargs.pop("left", 0)
+        bottom = kwargs.pop("bottom", 0)
+        left = kwargs.pop("left", 0)
+        if is_list_like(bottom):
+            bottom = np.array(bottom)
+        if is_list_like(left):
+            left = np.array(left)
+        self.bottom = bottom
+        self.left = left
 
         self.log = kwargs.pop("log", False)
         MPLPlot.__init__(self, data, **kwargs)
@@ -1698,12 +1692,6 @@ def __init__(self, data, **kwargs) -> None:
 
         self.ax_pos = self.tick_pos - self.tickoffset
 
-    def _args_adjust(self) -> None:
-        if is_list_like(self.bottom):
-            self.bottom = np.array(self.bottom)
-        if is_list_like(self.left):
-            self.left = np.array(self.left)
-
     # error: Signature of "_plot" incompatible with supertype "MPLPlot"
     @classmethod
     def _plot(  # type: ignore[override]
@@ -1874,8 +1862,6 @@ def __init__(self, data, kind=None, **kwargs) -> None:
         if (data < 0).any().any():
             raise ValueError(f"{self._kind} plot doesn't allow negative values")
         MPLPlot.__init__(self, data, kind=kind, **kwargs)
-
-    def _args_adjust(self) -> None:
         self.grid = False
         self.logy = False
         self.logx = False

pandas/plotting/_matplotlib/hist.py

@@ -58,36 +58,34 @@ def __init__(
         bottom: int | np.ndarray = 0,
         **kwargs,
     ) -> None:
-        self.bins = bins  # use mpl default
+        if is_list_like(bottom):
+            bottom = np.array(bottom)
         self.bottom = bottom
+
         self.xlabel = kwargs.get("xlabel")
         self.ylabel = kwargs.get("ylabel")
         # Do not call LinePlot.__init__ which may fill nan
         MPLPlot.__init__(self, data, **kwargs)  # pylint: disable=non-parent-init-called
 
-    def _args_adjust(self) -> None:
-        # calculate bin number separately in different subplots
-        # where subplots are created based on by argument
-        if is_integer(self.bins):
+        self.bins = self._adjust_bins(bins)
+
+    def _adjust_bins(self, bins: int | np.ndarray | list[np.ndarray]):
+        if is_integer(bins):
             if self.by is not None:
                 by_modified = unpack_single_str_list(self.by)
                 grouped = self.data.groupby(by_modified)[self.columns]
-                self.bins = [self._calculate_bins(group) for key, group in grouped]
+                bins = [self._calculate_bins(group, bins) for key, group in grouped]
             else:
-                self.bins = self._calculate_bins(self.data)
-
-        if is_list_like(self.bottom):
-            self.bottom = np.array(self.bottom)
+                bins = self._calculate_bins(self.data, bins)
+        return bins
 
-    def _calculate_bins(self, data: DataFrame) -> np.ndarray:
+    def _calculate_bins(self, data: DataFrame, bins) -> np.ndarray:
         """Calculate bins given data"""
         nd_values = data.infer_objects(copy=False)._get_numeric_data()
         values = np.ravel(nd_values)
         values = values[~isna(values)]
 
-        hist, bins = np.histogram(
-            values, bins=self.bins, range=self.kwds.get("range", None)
-        )
+        hist, bins = np.histogram(values, bins=bins, range=self.kwds.get("range", None))
         return bins
 
     # error: Signature of "_plot" incompatible with supertype "LinePlot"
@@ -211,9 +209,6 @@ def __init__(self, data, bw_method=None, ind=None, **kwargs) -> None:
         self.bw_method = bw_method
         self.ind = ind
 
-    def _args_adjust(self) -> None:
-        pass
-
     def _get_ind(self, y):
         if self.ind is None:
             # np.nanmax() and np.nanmin() ignores the missing values