Add orientation plot option

src/phytreeviz/treeviz.py

@@ -32,6 +32,7 @@ def __init__(
         format: str = "newick",
         height: float = 0.5,
         width: float = 8,
+        orientation: str = "right",
         align_leaf_label: bool = False,
         ignore_branch_length: bool = False,
         leaf_label_size: float = 12,
@@ -52,6 +53,8 @@ def __init__(
             Figure height per leaf node of tree
         width : float, optional
             Figure width
+        orientation : str, optional
+            Tree orientation (`right`|`left`)
         align_leaf_label: bool, optional
             If True, align leaf label.
         ignore_branch_length : bool, optional
@@ -91,6 +94,10 @@ def __init__(
         self._innode_label_xmargin_ratio = innode_label_xmargin_ratio
         self._reverse = reverse
         self._ax: Axes | None = None
+        if orientation in ("right", "left"):
+            self._orientation = orientation
+        else:
+            raise ValueError(f"{orientation=} is invalid (`right` or `left`).")
 
         self._node2label_props: dict[str, dict[str, Any]] = defaultdict(lambda: {})
         self._node2line_props: dict[str, dict[str, Any]] = defaultdict(lambda: {})
@@ -121,7 +128,10 @@ def figsize(self) -> tuple[float, float]:
     @property
     def xlim(self) -> tuple[float, float]:
         """Axes xlim"""
-        return (0, self.max_tree_depth)
+        if self._orientation == "left":
+            return (self.max_tree_depth, 0)
+        else:
+            return (0, self.max_tree_depth)
 
     @property
     def ylim(self) -> tuple[float, float]:
@@ -180,7 +190,7 @@ def ax(self) -> Axes:
         Can't access `ax` property before calling `tv.plotfig()` method
         """
         if self._ax is None:
-            err_msg = "Can't access ax property before calling `tv.plotfig() method"
+            err_msg = "Can't access ax property before calling `tv.plotfig()` method"
             raise ValueError(err_msg)
         return self._ax
 
@@ -464,6 +474,8 @@ def annotate(
         line_kws.setdefault("lw", 1)
         line_kws.update(dict(color=line_color, clip_on=False))
         text_kws.update(dict(size=text_size, color=text_color, va="center", ha="left"))
+        if self._orientation == "left":
+            text_kws.update(ha="right")
         if text_orientation == "horizontal":
             text_kws.update(dict(rotation=0))
         elif text_orientation == "vertical":
@@ -656,6 +668,9 @@ def text_on_branch(
         ypos2va = dict(top="bottom", center="center", bottom="top")
         ha, va = xpos, ypos2va[ypos]
 
+        if self._orientation == "left":
+            xpos = dict(left="right", right="left", center="center")[xpos]
+
         # Get text plot target node & xy coordinate
         target_node_name = self._search_target_node_name(query)
         xpos2xy = dict(
@@ -1000,6 +1015,8 @@ def _plot_node_label(self, ax: Axes) -> None:
             # Plot label
             text_kws = dict(size=label_size, ha="left", va="center_baseline")
             text_kws.update(self._node2label_props[str(node.name)])
+            if self._orientation == "left":
+                text_kws.update(ha="right")
             ax.text(x, y, s=node.name, **text_kws)  # type: ignore
 
     def _load_tree(self, data: str | Path | Tree, format: str) -> Tree: