Replace "inplace=" with chained arguments

metobscommon/util/nc.py

@@ -280,12 +280,9 @@ def summary_over_interval(frame, interval_width):
     include = [c for c in frame.columns if c not in exclude]
     gb = frame[include].resample(interval_width, closed='left')
 
-    low = gb.min()
-    low.rename(columns=lambda x: x + "_min", inplace=True)
-    high = gb.max()
-    high.rename(columns=lambda x: x + "_max", inplace=True)
-    mean = gb.mean()
-    mean.rename(columns=lambda x: x + "_mean", inplace=True)
+    low = gb.min().rename(columns=lambda x: x + "_min")
+    high = gb.max().rename(columns=lambda x: x + "_max")
+    mean = gb.mean().rename(columns=lambda x: x + "_mean")
 
     out_frames = pd.concat((low, high, mean), axis=1)