Code style improvements with pylint tool.

Fixed all pylint issues in mentat.geoip module. (Redmine issue: #3443)

.pylintrc-lib

@@ -297,7 +297,7 @@ ignored-classes=optparse.Values,thread._local,_thread._local
 # (useful for modules/projects where namespaces are manipulated during runtime
 # and thus existing member attributes cannot be deduced by static analysis. It
 # supports qualified module names, as well as Unix pattern matching.
-ignored-modules=rrdtool
+ignored-modules=rrdtool,geoip2.records
 
 # Show a hint with possible names when a member name was not found. The aspect
 # of finding the hint is based on edit distance.

lib/mentat/geoip.py

@@ -51,15 +51,19 @@ class GeoipService:
     """
     def __init__(self, asndb = None, citydb = None, countrydb = None):
         """
-
+        Initialize geolocation service with paths to desired database files.
         """
         self.fn_asndb     = asndb
         self.fn_citydb    = citydb
         self.fn_countrydb = countrydb
 
+        self.asndb     = None
+        self.citydb    = None
+        self.countrydb = None
+
     def __del__(self):
         """
-
+        Close internal geolocation database readers.
         """
         if self.fn_asndb:
             self.asndb.close()
@@ -70,16 +74,18 @@ class GeoipService:
 
     def setup(self):
         """
-
+        Setup internal geolocation database readers.
         """
         if self.fn_asndb:
             self.asndb = geoip2.database.Reader(self.fn_asndb)
         else:
             self.asndb = None
+
         if self.fn_citydb:
             self.citydb = geoip2.database.Reader(self.fn_citydb)
         else:
             self.citydb = None
+
         if self.fn_countrydb:
             self.countrydb = geoip2.database.Reader(self.fn_countrydb)
         else:
@@ -87,7 +93,7 @@ class GeoipService:
 
     def status(self):
         """
-
+        Display status of internal geolocation readers.
         """
         return {
             'asn':     self.fn_asndb,
@@ -97,7 +103,7 @@ class GeoipService:
 
     def lookup(self, ipaddr):
         """
-
+        Lookup given IP address in all databases.
         """
         result = {}
         if self.fn_asndb:
@@ -110,7 +116,7 @@ class GeoipService:
 
     def lookup_asn(self, ipaddr):
         """
-
+        Lookup given IP address in ASN database.
         """
         try:
 
@@ -126,7 +132,7 @@ class GeoipService:
 
     def lookup_city(self, ipaddr):
         """
-
+        Lookup given IP address in city database.
         """
         try:
 
@@ -148,7 +154,7 @@ class GeoipService:
 
     def lookup_country(self, ipaddr):
         """
-
+        Lookup given IP address in Country database.
         """
         try: