fix: define tax_columns below consistency
diff --git a/erpnext/accounts/report/purchase_register/purchase_register.py b/erpnext/accounts/report/purchase_register/purchase_register.py
index ed63e7f..a73c72c 100644
--- a/erpnext/accounts/report/purchase_register/purchase_register.py
+++ b/erpnext/accounts/report/purchase_register/purchase_register.py
@@ -127,7 +127,6 @@
 
 	expense_accounts = []
 	tax_accounts = []
-	tax_columns = []
 	unrealized_profit_loss_accounts = []
 
 	if invoice_list:
@@ -163,10 +162,11 @@
 	unrealized_profit_loss_account_columns = [
 		(account + ":Currency/currency:120") for account in unrealized_profit_loss_accounts
 	]
-
-	for account in tax_accounts:
-		if account not in expense_accounts:
-			tax_columns.append(account + ":Currency/currency:120")
+	tax_columns = [
+		(account + ":Currency/currency:120")
+		for account in tax_accounts
+		if account not in expense_accounts
+	]
 
 	columns = (
 		columns