fix: fixed dataframe method in ecdfplot

hydrodiy/plot/putils.py

@@ -517,7 +517,7 @@ def ecdfplot(ax, df, label_stat=None, label_stat_format="4.2f", \
         Dictionnary containing the line object for each column in df.
     """
     lines = {}
-    for name, se in df.iteritems():
+    for name, se in df.items():
         values = se.sort_values().values
         values = values[~np.isnan(values)]