Clean up Python 2.x workarounds

Since the next version will require Python 3.9 or later due to
relying on the zoneinfo module, go ahead and clean up code that
supported earlier versions of the interpreter as well as updating
documentation accordingly.

weather.py

@@ -11,18 +11,6 @@ weather_version = "2.4.4"
 radian_to_km = 6372.795484
 radian_to_mi = 3959.871528
 
-def pyversion(ref=None):
-    """Determine the Python version and optionally compare to a reference."""
-    import platform
-    ver = platform.python_version()
-    if ref:
-        return [
-            int(x) for x in ver.split(".")[:2]
-        ] >= [
-            int(x) for x in ref.split(".")[:2]
-        ]
-    else: return ver
-
 class Selections:
     """An object to contain selection data."""
     def __init__(self):
@@ -204,15 +192,7 @@ def get_uri(
     cachedir="."
 ):
     """Return a string containing the results of a URI GET."""
-    if pyversion("3"):
-        import urllib, urllib.error, urllib.request
-        URLError = urllib.error.URLError
-        urlopen = urllib.request.urlopen
-    else:
-        import urllib2 as urllib
-        URLError = urllib.URLError
-        urlopen = urllib.urlopen
-    import os, time
+    import os, time, urllib, urllib.error, urllib.request
     if cache_data:
         dcachedir = os.path.join( os.path.expanduser(cachedir), "datacache" )
         if not os.path.exists(dcachedir):
@@ -230,8 +210,8 @@ def get_uri(
         dcache_fd.close()
     else:
         try:
-            data = urlopen(uri).read().decode("utf-8")
-        except URLError:
+            data = urllib.request.urlopen(uri).read().decode("utf-8")
+        except urllib.error.URLError:
             if ignore_fail: return ""
             import os, sys
             sys.stderr.write("%s error: failed to retrieve\n   %s\n\n" % (
@@ -273,7 +253,7 @@ def get_metar(
         cacheage=cacheage,
         cachedir=cachedir
     )
-    if pyversion("3") and type(metar) is bytes: metar = metar.decode("utf-8")
+    if type(metar) is bytes: metar = metar.decode("utf-8")
     if verbose: return metar
     else:
         import re
@@ -333,7 +313,7 @@ def get_alert(
         cacheage=cacheage,
         cachedir=cachedir
     ).strip()
-    if pyversion("3") and type(alert) is bytes: alert = alert.decode("utf-8")
+    if type(alert) is bytes: alert = alert.decode("utf-8")
     if alert:
         if verbose: return alert
         else:
@@ -612,10 +592,8 @@ def get_options(config):
 
 def get_config():
     """Parse the aliases and configuration."""
-    if pyversion("3"): import configparser
-    else: import ConfigParser as configparser
+    import configparser, os
     config = configparser.ConfigParser()
-    import os
     rcfiles = [
         "/etc/weatherrc",
         "/etc/weather/weatherrc",
@@ -625,10 +603,7 @@ def get_config():
         ]
     for rcfile in rcfiles:
         if os.access(rcfile, os.R_OK):
-            if pyversion("3"):
-                config.read(rcfile, encoding="utf-8")
-            else:
-                config.read(rcfile)
+            config.read(rcfile, encoding="utf-8")
     for section in config.sections():
         if section != section.lower():
             if config.has_section(section.lower()):
@@ -640,9 +615,7 @@ def get_config():
 
 def integrate_search_cache(config, cachedir, setpath):
     """Add cached search results into the configuration."""
-    if pyversion("3"): import configparser
-    else: import ConfigParser as configparser
-    import os, time
+    import configparser, os, time
     scache_fn = os.path.join( os.path.expanduser(cachedir), "searches" )
     if not os.access(scache_fn, os.R_OK): return config
     scache_fd = open(scache_fn)
@@ -664,10 +637,7 @@ def integrate_search_cache(config, cachedir, setpath):
             pass
         return config
     scache = configparser.ConfigParser()
-    if pyversion("3"):
-        scache.read(scache_fn, encoding="utf-8")
-    else:
-        scache.read(scache_fn)
+    scache.read(scache_fn, encoding="utf-8")
     for section in scache.sections():
         if not config.has_section(section):
             config.add_section(section)
@@ -723,9 +693,7 @@ def guess(
     quiet=False
 ):
     """Find URIs using airport, gecos, placename, station, ZCTA/ZIP, zone."""
-    import codecs, datetime, time, os, re, sys
-    if pyversion("3"): import configparser
-    else: import ConfigParser as configparser
+    import codecs, configparser, datetime, time, os, re, sys
     datafiles = data_index(path)
     if re.match("[A-Za-z]{3}$", expression): searchtype = "airport"
     elif re.match("[A-Za-z0-9]{4}$", expression): searchtype = "station"
@@ -760,15 +728,9 @@ def guess(
         datafile = datafiles[dataname][0]
         if datafile.endswith(".gz"):
             import gzip
-            if pyversion("3"):
-                stations.read_string(
-                    gzip.open(datafile).read().decode("utf-8") )
-            else: stations.read_file( gzip.open(datafile) )
+            stations.read_string( gzip.open(datafile).read().decode("utf-8") )
         else:
-            if pyversion("3"):
-                stations.read(datafile, encoding="utf-8")
-            else:
-                stations.read(datafile)
+            stations.read(datafile, encoding="utf-8")
     else:
         message = "%s error: can't find \"%s\" data file\n" % (
             os.path.basename( sys.argv[0] ),
@@ -782,14 +744,9 @@ def guess(
         datafile = datafiles[dataname][0]
         if datafile.endswith(".gz"):
             import gzip
-            if pyversion("3"):
-                zones.read_string( gzip.open(datafile).read().decode("utf-8") )
-            else: zones.read_file( gzip.open(datafile) )
+            zones.read_string( gzip.open(datafile).read().decode("utf-8") )
         else:
-            if pyversion("3"):
-                zones.read(datafile, encoding="utf-8")
-            else:
-                zones.read(datafile)
+            zones.read(datafile, encoding="utf-8")
     else:
         message = "%s error: can't find \"%s\" data file\n" % (
             os.path.basename( sys.argv[0] ),
@@ -811,15 +768,10 @@ def guess(
             datafile = datafiles[dataname][0]
             if datafile.endswith(".gz"):
                 import gzip
-                if pyversion("3"):
-                    airports.read_string(
-                        gzip.open(datafile).read().decode("utf-8") )
-                else: airports.read_file( gzip.open(datafile) )
+                airports.read_string(
+                    gzip.open(datafile).read().decode("utf-8") )
             else:
-                if pyversion("3"):
-                    airports.read(datafile, encoding="utf-8")
-                else:
-                    airports.read(datafile)
+                airports.read(datafile, encoding="utf-8")
         else:
             message = "%s error: can't find \"%s\" data file\n" % (
                 os.path.basename( sys.argv[0] ),
@@ -903,15 +855,9 @@ def guess(
             datafile = datafiles[dataname][0]
             if datafile.endswith(".gz"):
                 import gzip
-                if pyversion("3"):
-                    zctas.read_string(
-                        gzip.open(datafile).read().decode("utf-8") )
-                else: zctas.read_file( gzip.open(datafile) )
+                zctas.read_string( gzip.open(datafile).read().decode("utf-8") )
             else:
-                if pyversion("3"):
-                    zctas.read(datafile, encoding="utf-8")
-                else:
-                    zctas.read(datafile)
+                zctas.read(datafile, encoding="utf-8")
         else:
             message = "%s error: can't find \"%s\" data file\n" % (
                 os.path.basename( sys.argv[0] ),
@@ -964,15 +910,9 @@ def guess(
             datafile = datafiles[dataname][0]
             if datafile.endswith(".gz"):
                 import gzip
-                if pyversion("3"):
-                    places.read_string(
-                        gzip.open(datafile).read().decode("utf-8") )
-                else: places.read_file( gzip.open(datafile) )
+                places.read_string( gzip.open(datafile).read().decode("utf-8") )
             else:
-                if pyversion("3"):
-                    places.read(datafile, encoding="utf-8")
-                else:
-                    places.read(datafile)
+                places.read(datafile, encoding="utf-8")
         else:
             message = "%s error: can't find \"%s\" data file\n" % (
                 os.path.basename( sys.argv[0] ),
@@ -1189,10 +1129,7 @@ def guess(
             )
         try:
             scache_existing = configparser.ConfigParser()
-            if pyversion("3"):
-                scache_existing.read(scache_fn, encoding="utf-8")
-            else:
-                scache_existing.read(scache_fn)
+            scache_existing.read(scache_fn, encoding="utf-8")
             if not scache_existing.has_section(search[0]):
                 scache_fd = codecs.open(scache_fn, "a", "utf-8")
                 scache_fd.writelines(search_cache)
@@ -1243,9 +1180,8 @@ def gecos(formatted):
     return tuple(coordinates)
 
 def correlate():
-    import codecs, csv, datetime, hashlib, os, re, sys, time, zipfile, zoneinfo
-    if pyversion("3"): import configparser
-    else: import ConfigParser as configparser
+    import codecs, configparser, csv, datetime, hashlib, os, re, sys, time
+    import zipfile, zoneinfo
     for filename in os.listdir("."):
         if re.match("[0-9]{4}_Gaz_counties_national.zip$", filename):
             gcounties_an = filename
@@ -2077,30 +2013,15 @@ def correlate():
     sys.stdout.write(message)
     sys.stdout.flush()
     airports = configparser.ConfigParser()
-    if pyversion("3"):
-        airports.read(airports_fn, encoding="utf-8")
-    else:
-        airports.read(airports_fn)
+    airports.read(airports_fn, encoding="utf-8")
     places = configparser.ConfigParser()
-    if pyversion("3"):
-        places.read(places_fn, encoding="utf-8")
-    else:
-        places.read(places_fn)
+    places.read(places_fn, encoding="utf-8")
     stations = configparser.ConfigParser()
-    if pyversion("3"):
-        stations.read(stations_fn, encoding="utf-8")
-    else:
-        stations.read(stations_fn)
+    stations.read(stations_fn, encoding="utf-8")
     zctas = configparser.ConfigParser()
-    if pyversion("3"):
-        zctas.read(zctas_fn, encoding="utf-8")
-    else:
-        zctas.read(zctas_fn)
+    zctas.read(zctas_fn, encoding="utf-8")
     zones = configparser.ConfigParser()
-    if pyversion("3"):
-        zones.read(zones_fn, encoding="utf-8")
-    else:
-        zones.read(zones_fn)
+    zones.read(zones_fn, encoding="utf-8")
     qalog = []
     places_nocentroid = 0
     places_nodescription = 0