Forward-port Python utilities to run polyglot under either Python 2 or 3.

For the moment most shebang lines still say 'python2' rather than just 'python'.
This is because the client code in gps/ hasn't been touched yet; the internal
imports break under Python 3 and that needs to be fixed.

14 files changed, 186 insertions, 160 deletions

diff --git a/build.txt b/build.txt
index 01fb4723..ee20a584 100644
--- a/build.txt
+++ b/build.txt
@@ -56,7 +56,7 @@ Necessary components for any build:
 
 |============================================================================
 |C compiler         | gpsd and client library are written in C
-|Python 2.x, x >= 6 | some code is generated from python scripts
+|Python 2.x, x >= 7 | some code is generated from python scripts
 |scons              | for executing the build recipe
 |============================================================================
 
diff --git a/gegps b/gegps
index 19623dbc..a4d00911 100755
--- a/gegps
+++ b/gegps
@@ -20,6 +20,8 @@
 # Modified by Chen Wei <weichen302@aol.com> for use with gpsd
 # Cleaned up and adapted for the GPSD project by Eric S. Raymond.
 
+from __future__ import print_function
+
 import sys, os, getopt
 import gps
 
@@ -87,7 +89,7 @@ if __name__ == "__main__":
     else:
         try:
             while True:
-                report = session.next()
+                report = next(session)
                 if report['class'] == 'TPV':
                     f = open(os.path.join(kmldir, 'Realtime_GPS.kml'), 'w')
                     f.write(kmlize(report))
@@ -95,6 +97,6 @@ if __name__ == "__main__":
         except StopIteration:
             pass
         except KeyboardInterrupt:
-            print 'gegpsd stopped '
+            print('gegpsd stopped ')
 
 # end
diff --git a/gpscap.py b/gpscap.py
index 422ecb93..998d2f7a 100644
--- a/gpscap.py
+++ b/gpscap.py
@@ -1,17 +1,20 @@
 """
-
 gpscap - GPS/AIS capability dictionary class.
 
 This file is Copyright (c) 2010 by the GPSD project
 BSD terms apply: see the file COPYING in the distribution root for details.
 """
-import ConfigParser
+from __future__ import print_function
 
+try:
+    import configparser
+except ImportError:
+    import ConfigParser as configparser
 
-class GPSDictionary(ConfigParser.RawConfigParser):
+class GPSDictionary(configparser.RawConfigParser):
     def __init__(self, *files):
         "Initialize the capability dictionary"
-        ConfigParser.RawConfigParser.__init__(self)
+        configparser.RawConfigParser.__init__(self)
         if not files:
             files = ["gpscap.ini", "/usr/share/gpsd/gpscap.ini"]
         self.read(files)
@@ -36,9 +39,9 @@ class GPSDictionary(ConfigParser.RawConfigParser):
         # Sanity check: All items must have a type field.
         for section in self.sections():
             if not self.has_option(section, "type"):
-                raise ConfigParser.Error("%s has no type" % section)
+                raise configparser.Error("%s has no type" % section)
             elif self.get(section, "type") not in ("engine", "vendor", "device"):
-                raise ConfigParser.Error("%s has invalid type" % section)
+                raise configparser.Error("%s has invalid type" % section)
         # Sanity check: All devices must point at a vendor object.
         # Side effect: build the lists of vendors and devices.
         self.vendors = []
@@ -52,9 +55,9 @@ class GPSDictionary(ConfigParser.RawConfigParser):
         for section in self.sections():
             if self.get(section, "type") == "device":
                 if not self.has_option(section, "vendor"):
-                    raise ConfigParser.Error("%s has no vendor" % section)
+                    raise configparser.Error("%s has no vendor" % section)
                 if self.get(section, "vendor") not in self.vendors:
-                    raise ConfigParser.Error("%s has invalid vendor" % section)
+                    raise configparser.Error("%s has invalid vendor" % section)
 
     def HTMLDump(self, ofp):
         thead = """<table style='border:1px solid gray;font-size:small;background-color:#CCCCCC'>
@@ -167,6 +170,6 @@ if __name__ == "__main__":
     try:
         d = GPSDictionary()
         d.HTMLDump(sys.stdout)
-    except ConfigParser.Error, e:
-        print >>sys.stderr, sys.argv[0]+":", e
-        raise SystemExit, 1
+    except configparser.Error as e:
+        sys.stderr.write(sys.argv[0]+":%s\n" % e)
+        raise SystemExit(1)
diff --git a/gpscat b/gpscat
index c401397c..17a68052 100755
--- a/gpscat
+++ b/gpscat
@@ -5,6 +5,8 @@
 #
 # Display GPS output.  Hexify it if necessary.
 #
+from __future__ import print_function
+
 import os, sys, termios, socket, select, getopt, curses.ascii
 import gps.packet as sniffer
 
@@ -42,9 +44,9 @@ if __name__ == '__main__':
     try:
         try:
             (options, arguments) = getopt.getopt(sys.argv[1:], "hps:tD:V")
-        except getopt.GetoptError, msg:
-            print "gpscat: " + str(msg)
-            raise SystemExit, 1
+        except getopt.GetoptError as msg:
+            print("gpscat: " + str(msg))
+            raise SystemExit(1)
 
         speed = None
         parity = None
@@ -67,11 +69,11 @@ if __name__ == '__main__':
                 debuglevel = BASELEVEL + int(val)
             elif switch == '-h':
                 printusage()
-                raise SystemExit, 0
+                raise SystemExit(0)
 
         if len(arguments) != 1:
             printusage()
-            raise SystemExit, 1
+            raise SystemExit(1)
 
         if "rfcomm" in arguments[0]:     # Bluetooth special case
             s = socket.socket(socket.AF_BLUETOOTH, socket.SOCK_STREAM, socket.BTPROTO_RFCOMM)
@@ -86,7 +88,7 @@ if __name__ == '__main__':
                 ispeed = ospeed = eval("termios.B%d" % speed)
             except AttributeError:
                 sys.stderr.write("gpscat: unknown baud rate %d\n" % speed)
-                raise SystemExit, 1
+                raise SystemExit(1)
             if stopbits:
                 cflag &= ~termios.CSIZE
                 cflag |= (termios.CS8, termios.CS7)[stopbits-1]
@@ -133,7 +135,7 @@ if __name__ == '__main__':
     except KeyboardInterrupt:
         if rawmode:
             sys.stdout.write("\n")
-        raise SystemExit, 0
+        raise SystemExit(0)
 
 # Local variables:
 # mode: python
diff --git a/gpsfake b/gpsfake
index 6c333969..6977e9b0 100755
--- a/gpsfake
+++ b/gpsfake
@@ -9,6 +9,8 @@
 # This file is Copyright (c) 2010 by the GPSD project
 # BSD terms apply: see the file COPYING in the distribution root for details.
 
+from __future__ import print_function
+
 import getopt
 import gps
 import gps.fake as gpsfake   # The "as" pacifies pychecker
@@ -19,6 +21,10 @@ import socket
 import sys
 import time
 
+try:
+    my_input = raw_input
+except NameError:
+    my_input = input
 
 class Baton:
     "Ship progress indications to stderr."
@@ -70,8 +76,8 @@ def hexdump(s):
 
 def fakehook(linenumber, fakegps):
     if len(fakegps.testload.sentences) == 0:
-        print >>sys.stderr, "fakegps: no sentences in test load."
-        raise SystemExit, 1
+        sys.stderr.write("fakegps: no sentences in test load.\n")
+        raise SystemExit(1)
     if linenumber % len(fakegps.testload.sentences) == 0:
         if singleshot and linenumber > 0:
             return False
@@ -86,9 +92,9 @@ def fakehook(linenumber, fakegps):
             ml = hexdump(ml)
         announce = fakegps.testload.legend % (linenumber % len(fakegps.testload.sentences) + 1) + ml
         if promptme:
-            raw_input(announce + "? ")
+            my_input(announce + "? ")
         else:
-            print announce
+            print(announce)
     if progress:
         baton.twirl()
     return True
@@ -96,9 +102,9 @@ def fakehook(linenumber, fakegps):
 if __name__ == '__main__':
     try:
         (options, arguments) = getopt.getopt(sys.argv[1:], "1bc:D:ghilm:no:pP:r:s:StTuvx")
-    except getopt.GetoptError, msg:
-        print "gpsfake: " + str(msg)
-        raise SystemExit, 1
+    except getopt.GetoptError as msg:
+        print("gpsfake: " + str(msg))
+        raise SystemExit(1)
 
     port = None
     progress = False
@@ -153,29 +159,29 @@ if __name__ == '__main__':
             tcp = True
         elif switch == '-T':
             sys.stdout.write("sys %s platform %s: WRITE_PAD = %.5f\n" % (sys.platform, platform.platform(), gpsfake.GetDelay(slow)))
-            raise SystemExit, 0
+            raise SystemExit(0)
         elif switch == '-u':
             udp = True
         elif switch == '-v':
             verbose += 1
         elif switch == '-h':
             sys.stderr.write("usage: gpsfake [-h] [-l] [-m monitor] [--D debug] [-o options] [-p] [-s speed] [-S] [-c cycle] [-b] logfile\n")
-            raise SystemExit, 0
+            raise SystemExit(0)
 
     try:
         pty.openpty()
     except (AttributeError, OSError):
-        print >>sys.stderr, "gpsfake: ptys not available, falling back to UDP."
+        sys.stderr.write("gpsfake: ptys not available, falling back to UDP.\n")
         udp = True
 
     if not arguments:
-        print >>sys.stderr, "gpsfake: requires at least one logfile argument."
-        raise SystemExit, 1
+        sys.stderr.write("gpsfake: requires at least one logfile argument.\n")
+        raise SystemExit(1)
 
     if progress:
         baton = Baton("Processing %s" % ",".join(arguments), "done")
     else:
-        print >>sys.stderr, "Processing %s" % ",".join(arguments)
+        sys.stderr.write("Processing %s\n" % ",".join(arguments))
 
     # Don't allocate a private port when cycling logs for client testing.
     if port is None and not pipe:
@@ -195,24 +201,24 @@ if __name__ == '__main__':
         for logfile in arguments:
             try:
                 test.gps_add(logfile, speed=speed, pred=fakehook, oneshot=singleshot)
-            except gpsfake.TestLoadError, e:
+            except gpsfake.TestLoadError as e:
                 sys.stderr.write("gpsfake: " + e.msg + "\n")
-                raise SystemExit, 1
-            except gpsfake.PacketError, e:
+                raise SystemExit(1)
+            except gpsfake.PacketError as e:
                 sys.stderr.write("gpsfake: " + e.msg + "\n")
-                raise SystemExit, 1
-            except gpsfake.DaemonError, e:
+                raise SystemExit(1)
+            except gpsfake.DaemonError as e:
                 sys.stderr.write("gpsfake: " + e.msg + "\n")
-                raise SystemExit, 1
-            except IOError, e:
+                raise SystemExit(1)
+            except IOError as e:
                 if e.filename is None:
                     sys.stderr.write("gpsfake: unknown internal I/O error %s\n" % e)
                 else:
                     sys.stderr.write("gpsfake: no such file as %s or file unreadable\n" % e.filename)
-                raise SystemExit, 1
+                raise SystemExit(1)
             except OSError:
                 sys.stderr.write("gpsfake: can't open pty.\n")
-                raise SystemExit, 1
+                raise SystemExit(1)
 
         try:
             if pipe:
@@ -228,15 +234,15 @@ if __name__ == '__main__':
                 # calls to gpsd_set_speed() in isync_detect()
                 time.sleep(1.4)
             test.run()
-        except socket.error, msg:
+        except socket.error as msg:
             sys.stderr.write("gpsfake: socket error %s.\n" % msg)
-            raise SystemExit, 1
-        except gps.client.json_error, e:
+            raise SystemExit(1)
+        except gps.client.json_error as e:
             sys.stderr.write("gpsfake: JSON error on line %s is %s.\n" % (repr(e.data), e.explanation))
-            raise SystemExit, 1
+            raise SystemExit(1)
         except KeyboardInterrupt:
             sys.stderr.write("gpsfake: aborted\n")
-            raise SystemExit, 1
+            raise SystemExit(1)
     finally:
         test.cleanup()
 
diff --git a/gpsprof b/gpsprof
index 2c124769..15374de4 100755
--- a/gpsprof
+++ b/gpsprof
@@ -181,11 +181,11 @@ class spaceplot(plotter):
     def postprocess(self):
         if not self.recentered:
             # centroid is just arithmetic avg of lat,lon
-            self.centroid = (sum(map(lambda x: x[0], self.fixes)) / len(self.fixes), sum(map(lambda x: x[1], self.fixes)) / len(self.fixes))
+            self.centroid = (sum([x[0] for x in self.fixes]) / len(self.fixes), sum([x[1] for x in self.fixes]) / len(self.fixes))
             # Sort fixes by distance from centroid
             self.fixes.sort(lambda x, y: cmp(self.d(self.centroid, x), self.d(self.centroid, y)))
             # Convert fixes to offsets from centroid in meters
-            self.recentered = map(lambda fix: gps.MeterOffset(self.centroid, fix[:2]), self.fixes)
+            self.recentered = [gps.MeterOffset(self.centroid, fix[:2]) for fix in self.fixes]
 
     def data(self):
         res = ""
@@ -446,7 +446,7 @@ if __name__ == '__main__':
             elif switch == '-h':
                 sys.stderr.write(
                     "usage: gpsprof [-h] [-D debuglevel] [-m threshold] [-n samplecount] [-d]\n"
-                    + "\t[-f {" + "|".join(map(lambda x: x.name, formatters)) + "}] [-s speed] [-t title] [-T terminal] [server[:port[:device]]]\n")
+                    + "\t[-f {" + "|".join([x.name for x in formatters]) + "}] [-s speed] [-t title] [-T terminal] [server[:port[:device]]]\n")
                 sys.exit(0)
 
         (host, port, device) = ("localhost", "2947", None)
diff --git a/gpssim.py b/gpssim.py
index a4dc4a82..fb686e67 100644
--- a/gpssim.py
+++ b/gpssim.py
@@ -5,7 +5,7 @@ A GPS simulator.
 
 This is proof-of-concept code, not production ready; some functions are stubs.
 """
-import sys, math, random, exceptions, time
+import sys, math, random, time
 import gps, gpslib
 
 # First, the mathematics.  We simulate a moving viewpoint on the Earth
@@ -77,9 +77,9 @@ class satellite:
 # class to generate output.
 
 
-class gpssimException(exceptions.Exception):
+class gpssimException(BaseException):
     def __init__(self, message, filename, lineno):
-        exceptions.Exception.__init__(self)
+        BaseException.__init__(self)
         self.message = message
         self.filename = filename
         self.lineno = lineno
@@ -90,14 +90,14 @@ class gpssimException(exceptions.Exception):
 
 class gpssim:
     "Simulate a moving sensor, with skyview."
-    active_PRNs = range(1, 24 + 1) + [134, ]
+    active_PRNs = list(range(1, 24 + 1)) + [134, ]
 
     def __init__(self, outfmt):
         self.ksv = ksv()
         self.ephemeris = {}
         # This sets up satellites at random.  Not really what we want.
         for prn in gpssim.active_PRNs:
-            for (prn, _satellite) in self.ephemeris.items():
+            for (prn, _satellite) in list(self.ephemeris.items()):
                 self.skyview[prn] = (random.randint(-60, +61),
                                      random.randint(0, 359))
         self.have_ephemeris = False
@@ -122,7 +122,7 @@ class gpssim:
         if command == "time":
             self.ksv.time = gps.isotime(fields[1])
         elif command == "location":
-            (self.lat, self.lon, self.alt) = map(float, fields[1:])
+            (self.lat, self.lon, self.alt) = list(map(float, fields[1:]))
         elif command == "course":
             self.ksv.time = float(fields[1])
         elif command == "speed":
@@ -130,7 +130,7 @@ class gpssim:
         elif command == "climb":
             self.ksv.climb = float(fields[1])
         elif command == "acceleration":
-            (self.ksv.h_acc, self.ksv.h_acc) = map(float, fields[1:])
+            (self.ksv.h_acc, self.ksv.h_acc) = list(map(float, fields[1:]))
         elif command == "snr":
             self.channels[int(fields[1])] = float(fields[2])
         elif command == "go":
@@ -170,10 +170,10 @@ class gpssim:
     def go(self, seconds):
         "Run the simulation for a specified number of seconds."
         for i in range(seconds):
-            self.ksv.next()
+            next(self.ksv)
             if self.have_ephemeris:
                 self.skyview = {}
-                for (prn, satellite) in self.ephemeris.items():
+                for (prn, satellite) in list(self.ephemeris.items()):
                     self.skyview[prn] = satellite.position(i)
             self.output.write(self.gpstype.report(self))
 
@@ -295,7 +295,7 @@ class NMEA:
                 (interval, sentence) = sentence
                 if self.counter % interval:
                     continue
-            out += apply(getattr(self, sentence), [sim])
+            out += getattr(self, sentence)(*[sim])
         self.counter += 1
         return out
 
@@ -304,7 +304,7 @@ class NMEA:
 if __name__ == "__main__":
     try:
         gpssim(NMEA).filter(sys.stdin, sys.stdout)
-    except gpssimException, e:
-        print >>sys.stderr, e
+    except gpssimException as e:
+        sys.stderr.write(repr(e)+"\n")
 
 # gpssim.py ends here.
diff --git a/jsongen.py.in b/jsongen.py.in
index 8155e43e..f3121de0 100644
--- a/jsongen.py.in
+++ b/jsongen.py.in
@@ -10,6 +10,8 @@
 # This code generates template declarations for AIS-JSON parsing from a
 # declarative specification of a JSON structure.
 #
+from __future__ import print_function
+
 import sys, getopt
 
 #
@@ -934,9 +936,9 @@ def generate(spec):
     attributes = [t[0] for t in spec["fieldmap"]]
     for attr in spec.get("stringbuffered", []):
         if attr not in attributes:
-            print >>sys.stderr, "buffered %s is not in base attributes of %s"\
-                % (attr, initname)
-            raise SystemExit, 1
+            sys.stderr.write("buffered %s is not in base attributes of %s\n"
+                             % (attr, initname))
+            raise SystemExit(1)
         elif attr not in outboard:
             report += "    char %s[JSON_VAL_MAX+1];\n" % attr
             outboard.append(attr)
@@ -958,8 +960,8 @@ def generate(spec):
                 elif default:
                     report += leader + ".len = %s},\n" % (default,)
                 else:
-                    print >>sys.stderr, "explicit length specification required"
-                    raise SystemExit, 1
+                    sys.stderr.write("explicit length specification required\n")
+                    raise SystemExit(1)
             report += """\
         {NULL}
     };
@@ -999,7 +1001,7 @@ def generate(spec):
         {NULL}
     };
 """
-    print report
+    print(report)
 
 if __name__ == '__main__':
     try:
@@ -1007,9 +1009,9 @@ if __name__ == '__main__':
         # In the future, this script will generate more different kinds
         # of code.
         (options, arguments) = getopt.getopt(sys.argv[1:], "", ["ais", "target="])
-    except getopt.GetoptError, msg:
-        print "jsongen.py: " + str(msg)
-        raise SystemExit, 1
+    except getopt.GetoptError as msg:
+        print("jsongen.py: " + str(msg))
+        raise SystemExit(1)
 
     spec = None
     target = None
@@ -1020,26 +1022,26 @@ if __name__ == '__main__':
             target = val
 
     if not target or not spec:
-        print "jsongen.py: must specify type and target."
-        raise SystemExit, 1
+        print("jsongen.py: must specify type and target.")
+        raise SystemExit(1)
 
     if target == 'parser':
-        print """/*
+        print("""/*
  * This is code generated by jsongen.py. Do not hand-hack it!
  */
  #define NITEMS(x) (int)(sizeof(x)/sizeof(x[0]))
 
 /*@ -fullinitblock */
 
-"""
+""")
         outboard = []
         for description in spec:
             generate(description)
-        print """
+        print("""
 /*@ +fullinitblock */
 
 /* Generated code ends. */
-"""
+""")
 # The following sets edit modes for GNU EMACS
 # Local Variables:
 # mode:python
diff --git a/leapsecond.py b/leapsecond.py
index 783cae33..e778d236 100755
--- a/leapsecond.py
+++ b/leapsecond.py
@@ -43,6 +43,7 @@ This file is Copyright (c) 2013 by the GPSD project
 BSD terms apply: see the file COPYING in the distribution root for details.
 
 """
+from __future__ import print_function
 
 import os, urllib, re, random, time, calendar, math, sys, signal
 
@@ -94,7 +95,7 @@ def isotime(s):
         msec = s - date
         date = time.strftime("%Y-%m-%dT%H:%M:%S", time.gmtime(s))
         return date + "." + repr(msec)[3:]
-    elif type(s) == type("") or type(s) == type(u""):
+    elif type(s) == type("") or type(s) == type(""):
         if s[-1] == "Z":
             s = s[:-1]
         if "." in s:
@@ -120,13 +121,13 @@ def retrieve():
             txt = ifp.read()
             ifp.close()
             if verbose:
-                print >>sys.stderr, "%s" % txt
+                sys.stderr.write("%s\n" % txt)
             m = re.search(regexp, txt)
             if m:
                 return int(m.group(1)) * sign - offset
         except IOError:
             if verbose:
-                print >>sys.stderr, "IOError: %s" % url
+                sys.stderr.write("IOError: %s\n" % url)
     return None
 
 
@@ -163,14 +164,14 @@ def save_leapseconds(outfile):
         try:
             fetchobj = urllib.urlopen(url)
         except IOError:
-            print >>sys.stderr, "Fetch from %s failed." % url
+            sys.stderr.write("Fetch from %s failed.\n" % url)
             continue
         # This code assumes that after 1980, leap-second increments are
         # always integrally one second and every increment is listed here
         fp = open(outfile, "w")
         for line in fetchobj:
             if verbose:
-                print >>sys.stderr, "%s" % line[:-1]
+                sys.stderr.write("%s\n" % line[:-1])
             if line.startswith(" 1980"):
                 skip = False
             if skip:
@@ -180,11 +181,11 @@ def save_leapseconds(outfile):
                 continue
             md = leapbound(fields[0], fields[1])
             if verbose:
-                print >>sys.stderr, "# %s" % md
+                sus.stderr.write("# %s\n" % md)
             fp.write(repr(iso_to_unix(md)) + "\t# " + str(md) + "\n")
         fp.close()
         return
-    print >>sys.stderr, "%s not updated." % outfile
+    sys.stderr.write("%s not updated.\n" % outfile)
 
 
 def fetch_leapsecs(filename):
@@ -292,9 +293,9 @@ def unix_to_iso(tv):
 def graph_history(filename):
     "Generate a GNUPLOT plot of the leap-second history."
     raw = fetch_leapsecs(filename)
-    (b, c, e) = leastsquares(zip(range(len(raw)), raw))
+    (b, c, e) = leastsquares(list(zip(list(range(len(raw))), raw)))
     e /= (60 * 60 * 24 * 7)
-    dates = map(lambda t: time.strftime("%Y-%m-%d", time.localtime(t)), raw)
+    dates = [time.strftime("%Y-%m-%d", time.localtime(t)) for t in raw]
     enddate = time.strftime("%Y-%m-%d", time.localtime(raw[-1]+16416000)) # Adding 190 days to scale
     fmt = ''
     fmt += '# Least-squares approximation of Unix time from leapsecond is:\n'
@@ -314,7 +315,7 @@ def graph_history(filename):
     for (i, (r, d)) in enumerate(zip(raw, dates)):
         fmt += "%d\t%s\t%s\n" % (i, r, d)
     fmt += 'e\n'
-    print fmt
+    print(fmt)
 
 
 def rfc822_to_unix(tv):
@@ -330,24 +331,24 @@ def unix_to_rfc822(tv):
 def printnext(val):
     "Compute Unix time correponsing to a scheduled leap second."
     if val[:3].lower() not in ("jun", "dec"):
-        print >>sys.stderr, "leapsecond.py: -n argument must begin with "\
-            "'Jun' or 'Dec'"
-        raise SystemExit, 1
+        sys.stderr.write("leapsecond.py: -n argument must begin with "\
+            "'Jun' or 'Dec'\n")
+        raise SystemExit(1)
     else:
         month = val[:3].lower()
         if len(val) != 7:
-            print >>sys.stderr, "leapsecond.py: -n argument must be of "\
-                "the form {jun|dec}nnnn."
-            raise SystemExit, 1
+            sys.stderr.wrrite("leapsecond.py: -n argument must be of "\
+                "the form {jun|dec}nnnn.\n")
+            raise SystemExit(1)
         try:
             year = int(val[3:])
         except ValueError:
-            print >>sys.stderr, "leapsecond.py: -n argument must end "\
-                "with a 4-digit year."
-            raise SystemExit, 1
+            sys.stderr.write("leapsecond.py: -n argument must end "\
+                "with a 4-digit year.\n")
+            raise SystemExit(1)
         # Date looks valid
         tv = leapbound(year, month)
-        print "%d       /* %s */" % (iso_to_unix(tv), tv)
+        print("%d       /* %s */" % (iso_to_unix(tv), tv))
 
 
 def leapbound(year, month):
@@ -368,8 +369,8 @@ def leapbound(year, month):
 
 
 def usage():
-    print __doc__
-    raise SystemExit, 0
+    print(__doc__)
+    raise SystemExit(0)
 
 if __name__ == '__main__':
     import getopt
@@ -381,27 +382,27 @@ if __name__ == '__main__':
             verbose = 1
         elif switch == '-f':    # Fetch USNO data to cache locally
             save_leapseconds(val)
-            raise SystemExit, 0
+            raise SystemExit(0)
         elif switch == '-g':  # Graph the leap_second history
             graph_history(val)
-            raise SystemExit, 0
+            raise SystemExit(0)
         elif switch == '-H':  # make leapsecond include
             sys.stdout.write(make_leapsecond_include(val))
-            raise SystemExit, 0
+            raise SystemExit(0)
         elif switch == '-i':  # Compute Unix time from RFC822 date
-            print rfc822_to_unix(val)
-            raise SystemExit, 0
+            print(rfc822_to_unix(val))
+            raise SystemExit(0)
         elif switch == '-n':  # Compute possible next leapsecond
             printnext(val)
-            raise SystemExit, 0
+            raise SystemExit(0)
         elif switch == '-o':  # Compute RFC822 date from Unix time
-            print unix_to_rfc822(float(val))
-            raise SystemExit, 0
+            print(unix_to_rfc822(float(val)))
+            raise SystemExit(0)
         elif switch == '-I':  # Compute Unix time from ISO8601 date
-            print isotime(val)
-            raise SystemExit, 0
+            print(isotime(val))
+            raise SystemExit(0)
         elif switch == '-O':  # Compute ISO8601 date from Unix time
-            print isotime(float(val))
-            raise SystemExit, 0
+            print(isotime(float(val)))
+            raise SystemExit(0)
 
 # End
diff --git a/maskaudit.py.in b/maskaudit.py.in
index 31be05ac..db6f57f8 100644
--- a/maskaudit.py.in
+++ b/maskaudit.py.in
@@ -11,11 +11,16 @@
 #
 # With -t, tabulate usage of defines to find unused ones.  Requires -c or -d.
 
-import commands
+from __future__ import print_function
+
 import getopt
 import glob
 import sys
 
+try:
+    from subprocess import getstatusoutput
+except ImportError:
+    from commands import getstatusoutput
 
 class SourceExtractor:
     def __init__(self, sourcefile, clientside):
@@ -39,11 +44,11 @@ class SourceExtractor:
                     self.primitive_masks.append((fields[1], fields[2]))
 
     def in_library(self, flag):
-        (status, _output) = commands.getstatusoutput("grep %s libgps_core.c libgps_json.c gpsctl.c" % flag)
+        (status, _output) = getstatusoutput("grep %s libgps_core.c libgps_json.c gpsctl.c" % flag)
         return status == 0
 
     def in_daemon(self, flag):
-        (status, _output) = commands.getstatusoutput("grep %s %s" % (flag, " ".join(self.daemonfiles)))
+        (status, _output) = getstatusoutput("grep %s %s" % (flag, " ".join(self.daemonfiles)))
         return status == 0
 
     def relevant(self, flag):
@@ -82,14 +87,14 @@ if __name__ == '__main__':
             banner = "Daemon"
 
         if tabulate:
-            print "%-14s	%8s" % (" ", banner)
+            print("%-14s	%8s" % (" ", banner))
             for (flag, value) in source.masks:
-                print "%-14s	%8s" % (flag, source.relevant(flag))
+                print("%-14s	%8s" % (flag, source.relevant(flag)))
         if pythonize:
             for (d, v) in source.masks:
                 if v[-1] == 'u':
                     v = v[:-1]
-                print "%-15s\t= %s" % (d, v)
+                print("%-15s\t= %s" % (d, v))
         if not pythonize and not tabulate:
             maxout = 0
             for (d, v) in source.primitive_masks:
@@ -100,7 +105,7 @@ if __name__ == '__main__':
                     if stem.endswith("_IS"):
                         stem = stem[:-3]
                     maxout += len(stem) + 1
-            print """/* This code is generated.  Do not hand-hack it! */
+            print("""/* This code is generated.  Do not hand-hack it! */
 
 /*
  * Also, beware that it is something of a CPU hog when called on every packet.
@@ -118,15 +123,15 @@ const char *gps_maskdump(gps_mask_t set)
     const struct {
         gps_mask_t      mask;
         const char      *name;
-    } *sp, names[] = {""" % (maxout + 3,)
+    } *sp, names[] = {""" % (maxout + 3,))
             for (flag, value) in clientside.primitive_masks + daemonside.primitive_masks:
                 stem = flag
                 if stem.endswith("_SET"):
                     stem = stem[:-4]
                 if stem.endswith("_IS"):
                     stem = stem[:-3]
-                print "        {%s,\t\"%s\"}," % (flag, stem)
-            print '''\
+                print("        {%s,\t\"%s\"}," % (flag, stem))
+            print('''\
     };
 
     memset(buf, '\\0', sizeof(buf));
@@ -141,7 +146,7 @@ const char *gps_maskdump(gps_mask_t set)
     (void)strlcat(buf, "}", sizeof(buf));
     return buf;
 }
-'''
+''')
     except KeyboardInterrupt:
         pass
 
diff --git a/test_maidenhead.py b/test_maidenhead.py
index 5463d01b..e8d5459d 100755
--- a/test_maidenhead.py
+++ b/test_maidenhead.py
@@ -7,6 +7,8 @@
 # Test conversions generated using
 #       http://f6fvy.free.fr/qthLocator/
 
+from __future__ import print_function
+
 import sys, gps.clienthelpers
 
 errors = 0
@@ -18,11 +20,11 @@ for (lat, lon, maidenhead, location) in [
 ]:
     converted = gps.clienthelpers.maidenhead(lat, lon)
     if converted != maidenhead:
-        print >>sys.stderr, "maidenhead test: from %s %s (%s) expected %s got %s" \
-            % (lat, lon, location, maidenhead, converted)
+        sys.stderr.write("maidenhead test: from %s %s (%s) expected %s got %s\n" \
+            % (lat, lon, location, maidenhead, converted))
         errors += 1
     else:
-        print "%s OK" % location
+        print("%s OK" % location)
 
 if errors:
     sys.exit(1)
diff --git a/valgrind-audit.py.in b/valgrind-audit.py.in
index 56e2517a..ea34a6a3 100644
--- a/valgrind-audit.py.in
+++ b/valgrind-audit.py.in
@@ -9,6 +9,8 @@
 # This file is Copyright (c) 2010 by the GPSD project
 # BSD terms apply: see the file COPYING in the distribution root for details.
 #
+from __future__ import print_function
+
 import sys, gps.fake
 
 debuglevel = 1
@@ -19,81 +21,81 @@ test.progress = sys.stderr.write
 
 try:
     test.spawn()
-    print "\n*** Test #1: Normal single-client-session behavior."
-    print "**** Add a GPS.\n"
+    print("\n*** Test #1: Normal single-client-session behavior.")
+    print("**** Add a GPS.\n")
     gps1 = test.gps_add("test/daemon/bu303-moving.log")
 
-    print "\n**** Add and remove a client.\n"
+    print("\n**** Add and remove a client.\n")
     c1 = test.client_add("w\n")
     test.gather(3)
     test.client_remove(c1)
 
-    print "\n**** Remove the GPS."
+    print("\n**** Remove the GPS.")
     test.gps_remove(gps1)
-    print "*** Test #1 complete.\n"
+    print("*** Test #1 complete.\n")
     test.wait(3)
 
     ######################################################################
 
-    print "\n*** Test #2: Successive non-overlapping client sessions."
-    print "**** Add a GPS.\n"
+    print("\n*** Test #2: Successive non-overlapping client sessions.")
+    print("**** Add a GPS.\n")
     gps1 = test.gps_add("test/daemon/bu303-climbing.log")
 
-    print "\n**** Add and remove first client.\n"
+    print("\n**** Add and remove first client.\n")
     c1 = test.client_add("w\n")
     test.gather(3)
     test.client_remove(c1)
     test.wait(3)
 
-    print "\n**** Add and remove second client.\n"
+    print("\n**** Add and remove second client.\n")
     c2 = test.client_add("w\n")
     test.gather(3)
     test.client_remove(c2)
     test.wait(3)
 
-    print "\n**** Remove the GPS."
+    print("\n**** Remove the GPS.")
     test.gps_remove(gps1)
-    print "*** Test #2 complete.\n"
+    print("*** Test #2 complete.\n")
     test.wait(3)
 
     ######################################################################
 
-    print "\n*** Test #3: Overlapping client sessions."
-    print "**** Add a GPS.\n"
+    print("\n*** Test #3: Overlapping client sessions.")
+    print("**** Add a GPS.\n")
     gps1 = test.gps_add("test/daemon/bu303-climbing.log")
 
-    print "\n**** Add first client.\n"
+    print("\n**** Add first client.\n")
     c1 = test.client_add("w\n")
     test.gather(2)
-    print "\n**** Add second client.\n"
+    print("\n**** Add second client.\n")
     c2 = test.client_add("w\n")
     test.gather(3)
-    print "\n**** Remove first client.\n"
+    print("\n**** Remove first client.\n")
     test.client_remove(c1)
     test.gather(2)
-    print "\n**** Remove second client.\n"
+    print("\n**** Remove second client.\n")
     test.client_remove(c2)
 
-    print "\n**** Remove the GPS."
+    print("\n**** Remove the GPS.")
     test.gps_remove(gps1)
-    print "*** Test #3 complete.\n"
+    print("*** Test #3 complete.\n")
 
     ######################################################################
 
-    print "\n*** Test #4: GPS removed while client still active."
-    print "**** Add a GPS.\n"
+    print("\n*** Test #4: GPS removed while client still active.")
+    print("**** Add a GPS.\n")
     gps1 = test.gps_add("test/daemon/bu303-moving.log")
 
-    print "\n**** Add a client.\n"
+    print("\n**** Add a client.\n")
     c1 = test.client_add("w\n")
     test.gather(3)
-    print "\n**** Remove the GPS."
+    print("\n**** Remove the GPS.")
     test.gps_remove(gps1)
     test.wait(3)
-    print "\n**** Remove the client.\n"
+    print("\n**** Remove the client.\n")
     test.client_remove(c1)
 
-    print "*** Test #4 complete.\n"
+    print("*** Test #4 complete.\n")
 finally:
     test.cleanup()
 
diff --git a/xgps b/xgps
index 0ac20dbf..a57863fc 100755
--- a/xgps
+++ b/xgps
@@ -6,6 +6,8 @@ xgps -- test client for gpsd
 usage: xgps [-D level] [-hV?] [-l degmfmt] [-u units] [server[:port[:device]]]
 '''
 
+from __future__ import print_function
+
 gui_about = '''\
 This is xgps, a test client for the gpsd daemon.
 
@@ -642,8 +644,7 @@ class Base:
             "AIS": self.aisbox}
 
         # Discard field labels and associate data hooks with their widgets
-        Base.gpsfields = map(lambda ((label, hook), widget): (hook, widget),
-                             zip(Base.gpsfields, gpswidgets))
+        Base.gpsfields = [(label_hook_widget[0][1], label_hook_widget[1]) for label_hook_widget in zip(Base.gpsfields, gpswidgets)]
 
     def view_toggle(self, action):
         # print "View toggle:", action.get_active(), action.get_name()
@@ -874,7 +875,7 @@ if __name__ == "__main__":
             elif opt == '-u':
                 unit_system = val
             elif opt in ('-?', '-h', '--help'):
-                print __doc__
+                print(__doc__)
                 sys.exit(0)
             elif opt == 'V':
                 sys.stderr.write("xgps 1.0\n")
diff --git a/xgpsspeed b/xgpsspeed
index 7bbf7c59..6e9957c4 100755
--- a/xgpsspeed
+++ b/xgpsspeed
@@ -296,7 +296,7 @@ class NauticalSpeedometer(Speedometer):
         s_long = self.long_inset(rspeed)
         s_middle = self.mid_inset(radius)
         s_short = self.short_inset(radius)
-        for i in xrange(11):
+        for i in range(11):
             # draw the large ticks
             alpha = (8 - i) * pi / 6
             self.cr.move_to(*NauticalSpeedometer.polar2xy(rspeed, alpha, x, y))
@@ -308,7 +308,7 @@ class NauticalSpeedometer(Speedometer):
             stxt = (self.maxspeed / 10) * i
             self.draw_text(xf, yf, stxt, fontsize=radius / 15)
 
-        for i in xrange(1, 11):
+        for i in range(1, 11):
             # middle tick
             alpha = (8 - i) * pi / 6
             beta = (17 - 2 * i) * pi / 12
@@ -316,7 +316,7 @@ class NauticalSpeedometer(Speedometer):
             self.cr.line_to(*NauticalSpeedometer.polar2xy(rspeed - s_middle, beta, x, y))
 
             #  short tick
-            for n in xrange(10):
+            for n in range(10):
                 gamma = alpha + n * pi / 60
                 self.cr.move_to(*NauticalSpeedometer.polar2xy(rspeed, gamma, x, y))
                 self.cr.line_to(*NauticalSpeedometer.polar2xy(rspeed - s_short, gamma, x, y))
@@ -331,7 +331,7 @@ class NauticalSpeedometer(Speedometer):
         self.cr.set_source_rgba(0, 0, 0)
 
         # heading label 90/180/270
-        for n in xrange(0, 4):
+        for n in range(0, 4):
             label = str(n * 90)
             # self.cr.set_source_rgba(0, 1, 0)
             # radius * (1 + NauticalSpeedometer.HEADING_SAT_GAP),
@@ -367,7 +367,7 @@ class NauticalSpeedometer(Speedometer):
         short_inset = self.short_inset(radius)
 
         # draw the large ticks
-        for i in xrange(12):
+        for i in range(12):
             agllong = i * pi / 6
             self.cr.move_to(*NauticalSpeedometer.polar2xy(radius - long_inset, agllong, x, y))
             self.cr.line_to(*NauticalSpeedometer.polar2xy(radius, agllong, x, y))
@@ -381,7 +381,7 @@ class NauticalSpeedometer(Speedometer):
             self.cr.line_to(*NauticalSpeedometer.polar2xy(radius, aglmid, x, y))
 
             #  short tick
-            for n in xrange(1, 10):
+            for n in range(1, 10):
                 aglshrt = agllong + n * pi / 60
                 self.cr.move_to(*NauticalSpeedometer.polar2xy(radius - short_inset, aglshrt, x, y))
                 self.cr.line_to(*NauticalSpeedometer.polar2xy(radius, aglshrt, x, y))