fix ruff tests

gliderpy/plotting.py

@@ -95,38 +95,39 @@ def plot_transect(
 @register_dataframe_method
 def plot_ctd(
     df: pd.DataFrame,
-    idx: int,
+    profile_number: int,
     var: str,
     ax: plt.Axes = None,
-    color: str = None
+    color: str | None = None,
 ) -> tuple:
     """Make a CTD profile plot of pressure vs property
     depending on what variable was chosen.
-    :param idx: index of position  
+
+    :param profile_number: profile number of CTD
     :param var: variable to plot against pressure
     :param ax: existing axis to plot on (default: None)
     :param color: color for the plot line (default: None)
     :return: figure, axes
     """
     g = df.groupby(["longitude", "latitude"])
-    profile = g.get_group((list(g.groups)[idx]))
+    profile = g.get_group(list(g.groups)[profile_number])
 
     if ax is None:
         fig, ax1 = plt.subplots(figsize=(5, 6))
         ax1.plot(profile[var], -profile["pressure"], label=var, color=color)
-        ax1.set_ylabel('Pressure')
+        ax1.set_ylabel("Pressure")
         ax1.set_xlabel(var)
         ax1.legend()
         return fig, ax1
-    else:
-        fig = ax.get_figure()
-        ax2 = ax.twiny()  # Create a new twinned axis
-        ax2.plot(profile[var], -profile["pressure"], label=var, color=color)
-        ax2.set_xlabel(var)
-        
-        # Handle legends
-        lines, labels = ax.get_legend_handles_labels()
-        lines2, labels2 = ax2.get_legend_handles_labels()
-        ax.legend(lines + lines2, labels + labels2, loc="lower center")
-        
-        return fig, ax2
+
+    fig = ax.get_figure()
+    ax2 = ax.twiny()  # Create a new twinned axis
+    ax2.plot(profile[var], -profile["pressure"], label=var, color=color)
+    ax2.set_xlabel(var)
+
+    # Handle legends
+    lines, labels = ax.get_legend_handles_labels()
+    lines2, labels2 = ax2.get_legend_handles_labels()
+    ax.legend(lines + lines2, labels + labels2, loc="lower center")
+
+    return fig, ax2