renamed extract chain file

scripts/chain_extract.py

@@ -0,0 +1,30 @@
+#!/usr/bin/python3
+
+#=======================================================================
+# TASK: select specified chains from the pdb & save a cropped PDB with
+# the selected chains. Useful for dimer, etc modelling.
+
+# link for saving each chain as a separate file
+# https://stackoverflow.com/questions/11685716/how-to-extract-chains-from-a-pdb-file
+#=======================================================================
+
+from Bio.PDB import PDBParser, PDBIO, Select
+
+io = PDBIO()
+pdb = PDBParser().get_structure("3byw", "3byw.pdb")
+
+
+# Select() Method to return True for every chain in 'chains'
+class ChainSelect(Select):
+   def accept_chain(self, chain):
+       #print dir(chain)
+       if chain.id in chains:
+           return 1
+       else:
+           return 0
+
+if __name__ == '__main__':
+    chains = ['G', 'H'] # specify selected chains
+    io.set_structure(pdb)
+    io.save(pdb.get_id() + "_crop.pdb", ChainSelect())
+