Explicitly convert filter to list wherever necessary

frappe/core/doctype/doctype/doctype.py

@@ -451,7 +451,7 @@ def validate_fields(meta):
 
 	def check_dynamic_link_options(d):
 		if d.fieldtype=="Dynamic Link":
-			doctype_pointer = filter(lambda df: df.fieldname==d.options, fields)
+			doctype_pointer = list(filter(lambda df: df.fieldname==d.options, fields))
 			if not doctype_pointer or (doctype_pointer[0].fieldtype not in ("Link", "Select")) \
 				or (doctype_pointer[0].fieldtype=="Link" and doctype_pointer[0].options!="DocType"):
 				frappe.throw(_("Options 'Dynamic Link' type of field must point to another Link Field with options as 'DocType'"))

frappe/core/doctype/module_def/module_def.py

@@ -30,7 +30,7 @@ class ModuleDef(Document):
 			with open(frappe.get_app_path(self.app_name, "modules.txt"), "r") as f:
 				content = f.read()
 				if not self.name in content.splitlines():
-					modules = filter(None, content.splitlines())
+					modules = list(filter(None, content.splitlines()))
 					modules.append(self.name)
 
 			if modules:

frappe/core/page/data_import_tool/importer.py

@@ -72,7 +72,7 @@ def upload(rows = None, submit_after_import=None, ignore_encoding_errors=False,
 		return [], -1
 
 	def filter_empty_columns(columns):
-		empty_cols = filter(lambda x: x in ("", None), columns)
+		empty_cols = list(filter(lambda x: x in ("", None), columns))
 
 		if empty_cols:
 			if columns[-1*len(empty_cols):] == empty_cols: