MAINT: Use pd.concat, DataFrame.append deprecated

tabedzki · has2k1 · commit e9cc70dd544f · 2022-03-04T14:15:36.000-05:00
closes #571
diff --git a/plotnine/facets/facet.py b/plotnine/facets/facet.py
@@ -485,7 +485,7 @@ def combine_vars(data, environment=None, vars=None, drop=True):
         ].drop_duplicates()
         if not drop:
             new = unique_combs(new)
-        base = base.append(cross_join(old, new), ignore_index=True)
+        base = pd.concat(base, cross_join(old, new), ignore_index=True)
 
     if len(base) == 0:
         raise PlotnineError(
diff --git a/plotnine/utils.py b/plotnine/utils.py
@@ -368,7 +368,7 @@ def join_keys(x, y, by=None):
     if isinstance(by, tuple):
         by = list(by)
 
-    joint = x[by].append(y[by], ignore_index=True)
+    joint = pd.concat([x[by], y[by]], ignore_index=True)
     keys = ninteraction(joint, drop=True)
     keys = np.asarray(keys)
     nx, ny = len(x), len(y)
