Fix for polars 1.33.0 (dtype becoming mandatory)

charles-turner-1 · charles-turner-1 · commit a5e1fb24bf16 · 2025-09-04T19:38:54.000+08:00
diff --git a/intake_esm/cat.py b/intake_esm/cat.py
@@ -662,8 +662,10 @@ def _read_csv_pl(self) -> FramesModel:
                 .str.replace('^.', '[')  # Replace first/last chars with [ or ].
                 .str.replace('.$', ']')  # set/tuple => list
                 .str.replace(',]$', ']')  # Remove trailing commas
-                .str.replace_all("'", '"')
-                .str.json_decode()  # This is to do with the way polars reads json - single versus double quotes
+                .str.replace_all(
+                    "'", '"'
+                )  # This is to do with the JSON spec- single versus double quotes
+                .str.json_decode(dtype=pl.List(pl.Utf8))
                 for colname in converters.keys()
             ]
         )

Original file line number	Diff line number	Diff line change
`@@ -662,8 +662,10 @@ def _read_csv_pl(self) -> FramesModel:`
`662`	`662`	`.str.replace('^.', '[') # Replace first/last chars with [ or ].`
`663`	`663`	`.str.replace('.$', ']') # set/tuple => list`
`664`	`664`	`.str.replace(',]$', ']') # Remove trailing commas`
`665`		`- .str.replace_all("'", '"')`
`666`		`- .str.json_decode() # This is to do with the way polars reads json - single versus double quotes`
	`665`	`+ .str.replace_all(`
	`666`	`+ "'", '"'`
	`667`	`+ ) # This is to do with the JSON spec- single versus double quotes`
	`668`	`+ .str.json_decode(dtype=pl.List(pl.Utf8))`
`667`	`669`	`for colname in converters.keys()`
`668`	`670`	`]`
`669`	`671`	`)`