Fix cluster file loading bug in pdb_data.py (#396)

* Fix cluster file loading bug in `pdb_data.py`

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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* Update CHANGELOG.md

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

CHANGELOG.md

@@ -3,7 +3,8 @@
 #### Bugfixes
 * Add support for DSSP >4. Backwards compatibility is still supported. [#355](https://github.com/a-r-j/graphein/pull/355). Fixes [#353](https://github.com/a-r-j/graphein/issues/353).
 * Fixes bug where RSA features are missing from nodes with insertion codes. [#355](https://github.com/a-r-j/graphein/pull/355). Fixes [#354](https://github.com/a-r-j/graphein/issues/353).
-* Fix bug where the `deprotonate` argument is not wired up to `graphein.protein.graphs.construct_graphs`. [#375](https://github.com/a-r-j/graphein/pull/375)
+* Fix bug where the `deprotonate` argument is not wired up to `graphein.protein.graphs.construct_graphs` [#375](https://github.com/a-r-j/graphein/pull/375)
+* Fix cluster file loading bug in `pdb_data.py` [#396](https://github.com/a-r-j/graphein/pull/396)
 
 #### Misc
 * bumped logging level down from `INFO` to `DEBUG` at several places to reduced output length [#391](https://github.com/a-r-j/graphein/pull/391)

graphein/ml/datasets/pdb_data.py

@@ -1396,9 +1396,7 @@ def cluster(
             )
 
         # Read FASTA
-        df = self.from_fasta(
-            ids="chain", filename=str(self.root_dir / cluster_fname)
-        )
+        df = self.from_fasta(ids="chain", filename=str(cluster_fname))
         if update:
             self.df = df