diff --git a/modules/attribute_formatter.py b/modules/attribute_formatter.py
index 484d8c2e61234531de57c6d4b8c1d1919f0fe2fc..4c6f625f10a4539b88ced27d835cfe34e85e74cd 100644
--- a/modules/attribute_formatter.py
+++ b/modules/attribute_formatter.py
@@ -1,22 +1,26 @@
 """ This module handles the creation of simple vagrant commands from yaml
 attributes. """
 
+def _format_variable_name(key, variable_type, mappings):
+    """ Formats the variable to the required vagrantfile definition. """
+    return "device." + mappings[variable_type][key] + " = "
+
 
 def _format_and_add(key, value, mappings, device_definition):
     """ Formats and adds the definition of a simple attribute. """
 
-    if key in mappings['string']:
+    if key in mappings["string"]:
         device_definition.append(
-            'device.' + mappings['string'][key]
-            + ' = \"' + str(value) + '\"')
-    elif key in mappings['integer']:
+            _format_variable_name(key, "string", mappings)
+            + '\"' + str(value) + '\"')
+    elif key in mappings["integer"]:
         device_definition.append(
-            'device.' + mappings['integer'][key]
-            + ' = ' + str(value))
-    elif key in mappings['boolean']:
+            _format_variable_name(key, "integer", mappings)
+            + str(value))
+    elif key in mappings["boolean"]:
         device_definition.append(
-            'device.' + mappings['boolean'][key]
-            + ' = ' + str(value).lower())
+            _format_variable_name(key, "boolean", mappings)
+            + str(value).lower())
 
 
 def add_simple_commands(device, mappings, device_definition):
diff --git a/modules/device_creator.py b/modules/device_creator.py
index ae5923889787033ee13f8be0ec52a61c2bcadfe8..ae7e9362df4d1bee460befc77530aa3b43ee9e10 100644
--- a/modules/device_creator.py
+++ b/modules/device_creator.py
@@ -7,35 +7,17 @@ from modules.attribute_formatter import add_simple_commands
 from modules.provider import add_prov_attributes, add_router_specification
 from modules.network_parser import add_networks, add_router_ip
 
-
-def _open_yml(yml_file_name):
-    """ Opens the input yaml file. """
-    try:
-        ymlfile = open(str(yml_file_name))
-        yml = yaml.safe_load(ymlfile)
-        return yml
-    except IOError:
-        print("Error: file does not exist.")
-
-
-def _open_mappings():
-    """ Opens the file with name mappings. """
-    try:
-        mapping_file = open("name_mapping/mapping.yml")
-        mappings = yaml.safe_load(mapping_file)
-        return mappings
-    except IOError:
-        print("Error: cannot find mappings.")
+MAPPING_FILE = "name_mapping/mapping.yml"
+FLAVORS_FILE = "name_mapping/flavors.yml"
 
 
-def _open_flavors():
-    """ Opens the file with flavor definitions. """
+def _open_file(file_name):
+    """ Opens and returns a file from the argument. """
     try:
-        flavors_file = open("name_mapping/flavors.yml")
-        flavors = yaml.safe_load(flavors_file)
-        return flavors
+        input_file = open(str(file_name))
+        return yaml.safe_load(input_file)
     except IOError:
-        print("Error: cannot find the list of flavors.")
+        print("Error: Cannot find a required file.")
 
 
 def _create_hosts(yml, mappings, flavors):
@@ -66,11 +48,11 @@ def _create_routers(yml):
 
 
 def create_devices(yml_file_name):
-    """ Returns a marged dictionary of host and router definitions. """
+    """ Returns a merged dictionary of host and router definitions. """
 
-    yml = _open_yml(yml_file_name)
-    mappings = _open_mappings()
-    flavors = _open_flavors()
+    yml = _open_file(yml_file_name)
+    mappings = _open_file(MAPPING_FILE)
+    flavors = _open_file(FLAVORS_FILE)
 
     return {
         **_create_hosts(yml, mappings, flavors),
diff --git a/modules/network_parser.py b/modules/network_parser.py
index 9a85a4bcba36c0224ea7e667c82c4941ba01d576..920313c425f86df8690a356abaf8110aaaaa2462 100644
--- a/modules/network_parser.py
+++ b/modules/network_parser.py
@@ -7,14 +7,9 @@ def _find_ip(hostname, mappings, device_type):
     """ Finds the ip address of a device. """
 
     for mapping in mappings:
-        if device_type == 'host':
-            if mapping['host'] and mapping['host'] == hostname:
+        if device_type in ('host', 'router'):
+            if mapping[device_type] and mapping[device_type] == hostname:
                 return mapping['ip']
-        elif device_type == 'router':
-            if mapping['router'] and mapping['router'] == hostname:
-                return mapping['ip']
-
-    return None
 
 
 def _add_ip(hostname, mappings, device_type, definitions):
diff --git a/modules/provider.py b/modules/provider.py
index 343187c91fb7d4f95251d9725575bffe69ffb0f1..a8f180b1d86ef6aff016a47639096bfcfa4cff6f 100644
--- a/modules/provider.py
+++ b/modules/provider.py
@@ -51,12 +51,12 @@ def add_prov_attributes(host, flavors, provider_attributes, definitions):
 def add_router_specification(router, definitions):
     """ Adds the default specification for a router. """
 
-    ROUTER_BOX = "generic/debian10"
-    ROUTER_MEMORY = 256
+    router_box = "generic/debian10"
+    router_memory = 256
 
     definitions[router['name']].append(
-        "device.vm.box = \"" + ROUTER_BOX + "\"")
+        "device.vm.box = \"" + router_box + "\"")
     definitions[router['name']].append(
         "device.vm.provider \"virtualbox\" do |vb|")
-    definitions[router['name']].append("  vb.memory = " + str(ROUTER_MEMORY))
+    definitions[router['name']].append("  vb.memory = " + str(router_memory))
     definitions[router['name']].append("end")