Observed = True as suggested here pandas-dev/pandas#30552

paulrougieux · paulrougieux · commit a5eb59f823eb · 2020-01-14T12:19:05.000+01:00
diff --git a/cbmcfs3_runner/post_processor/ipcc.py b/cbmcfs3_runner/post_processor/ipcc.py
@@ -72,7 +72,7 @@ def pool_indicators_long(self):
         index = self.parent.classifiers_names
         index = index + ['ipcc_pool', 'time_step', 'year']
         df = (df
-              .groupby(index)
+              .groupby(index, observed=True)
               .agg({'tc':sum})
               .reset_index()
               )

Original file line number	Diff line number	Diff line change
`@@ -72,7 +72,7 @@ def pool_indicators_long(self):`
`72`	`72`	`index = self.parent.classifiers_names`
`73`	`73`	`index = index + ['ipcc_pool', 'time_step', 'year']`
`74`	`74`	`df = (df`
`75`		`- .groupby(index)`
	`75`	`+ .groupby(index, observed=True)`
`76`	`76`	`.agg({'tc':sum})`
`77`	`77`	`.reset_index()`
`78`	`78`	`)`