text_viz.py: waterfall -> cascade.

It is shorter, easier to remember for me, and the meaning
seems slightly more accurate.

ete4/core/text_viz.py

@@ -13,25 +13,25 @@
 
 
 def to_str(tree, show_internal=True, compact=False, props=None,
-           px=None, py=0, px0=0, waterfall=False):
+           px=None, py=0, px0=0, cascade=False):
     """Return a string containing an ascii drawing of the tree.
 
     :param show_internal: If True, show the internal nodes too.
     :param compact: If True, use exactly one line per tip.
     :param props: List of node properties to show. If None, show all.
     :param px, py, px0: Paddings (x, y, x for leaves). Overrides `compact`.
-    :param waterfall: Use a waterfall representation. Overrides
+    :param cascade: Use a cascade representation. Overrides
         `show_internal`, `compact`, `px`, `py`, `px0`.
     """
-    if not waterfall:
+    if not cascade:
         px = px if px is not None else (0 if show_internal else 1)
         py = py if py is not None else (0 if compact else 1)
 
         lines, _ = ascii_art(tree, show_internal, props, px, py, px0)
         return '\n'.join(lines)
     else:
         px = px if px is not None else 1
-        return to_waterfall(tree, props, px)
+        return to_cascade(tree, props, px)
 
 
 # For representations like:
@@ -133,8 +133,8 @@ def add_base(line, px, px0, txt, show_internal):
 #   │ └─╴d
 #   └─╴f
 
-def to_waterfall(tree, props=None, px=1, are_last=None):
-    """Return string with a visual representation of the tree as a waterfall."""
+def to_cascade(tree, props=None, px=1, are_last=None):
+    """Return string with a visual representation of the tree as a cascade."""
     are_last = are_last or []
 
     # Node description (including all the requested properties).
@@ -144,7 +144,7 @@ def to_waterfall(tree, props=None, px=1, are_last=None):
 
     branches = get_branches_repr(are_last, tree.is_leaf, px)
 
-    wf = lambda n, lasts: to_waterfall(n, props, px, lasts)  # shortcut
+    wf = lambda n, lasts: to_cascade(n, props, px, lasts)  # shortcut
 
     return '\n'.join([branches + descr] +
                      [wf(n, are_last + [False]) for n in tree.children[:-1]] +

ete4/core/tree.pyx

@@ -312,18 +312,18 @@ cdef class Tree(object):
         return self.to_str(show_internal=False, compact=True, props=['name'])
 
     def to_str(self, show_internal=True, compact=False, props=None,
-               px=None, py=None, px0=0, waterfall=False):
+               px=None, py=None, px0=0, cascade=False):
         """Return a string containing an ascii drawing of the tree.
 
         :param show_internal: If True, show the internal nodes too.
         :param compact: If True, use exactly one line per tip.
         :param props: List of node properties to show. If None, show all.
         :param px, py, px0: Paddings (x, y, x for leaves). Overrides `compact`.
-        :param waterfall: Use a waterfall representation. Overrides
+        :param cascade: Use a cascade representation. Overrides
             `show_internal`, `compact`, `px`, `py`, `px0`.
         """
         return text_viz.to_str(self, show_internal, compact, props,
-                               px, py, px0, waterfall)
+                               px, py, px0, cascade)
 
     def __contains__(self, item):
         """Return True if the tree contains the given item.

tests/test_tree.py

@@ -167,7 +167,7 @@ def test_to_str(self):
          ╰─┬╴c
            ╰╴d
         """))
-        self.assertEqual(t.to_str(props=['name'], waterfall=True), strip("""
+        self.assertEqual(t.to_str(props=['name'], cascade=True), strip("""
         ⊗
         ├─┐x
         │ ├─╴a