Forward-port gps/ Python client code to run polyglot under Python 2 or 3.

Verified by testing gpsprof under both versions. leapecond.py is also OK.

Not yet polyglot: gegps, gpscap.py, gpscat, gpsfake, jsongen.py, maskaudit.py,
test_maidenhead.py, valgrind_audit.py, xgps, xgpsspeed.

7 files changed, 45 insertions, 35 deletions

diff --git a/gps/__init__.py b/gps/__init__.py
index cb73669c..05bce897 100644
--- a/gps/__init__.py
+++ b/gps/__init__.py
@@ -6,8 +6,8 @@
 api_major_version = 5   # bumped on incompatible changes
 api_minor_version = 0   # bumped on compatible changes
 
-from gps import *
-from misc import *
+from .gps import *
+from .misc import *
 
 # The 'client' module exposes some C utility functions for Python clients.
 # The 'packet' module exposes the packet getter via a Python interface.
diff --git a/gps/client.py b/gps/client.py
index 6a996714..2ff06f93 100644
--- a/gps/client.py
+++ b/gps/client.py
@@ -1,7 +1,7 @@
 # This file is Copyright (c) 2010 by the GPSD project
 # BSD terms apply: see the file COPYING in the distribution root for details.
 #
-import time, socket, sys, select, exceptions
+import time, socket, sys, select
 
 if sys.hexversion >= 0x2060000:
     import json			# For Python 2.6
@@ -11,9 +11,9 @@ else:
 GPSD_PORT = "2947"
 
 
-class json_error(exceptions.Exception):
+class json_error(BaseException):
     def __init__(self, data, explanation):
-        exceptions.Exception.__init__(self)
+        BaseException.__init__(self)
         self.data = data
         self.explanation = explanation
 
@@ -42,7 +42,7 @@ class gpscommon:
             try:
                 port = int(port)
             except ValueError:
-                raise socket.error, "nonnumeric port"
+                raise socket.error("nonnumeric port")
         # if self.verbose > 0:
         #    print 'connect:', (host, port)
         msg = "getaddrinfo returns an empty list"
@@ -53,13 +53,13 @@ class gpscommon:
                 self.sock = socket.socket(af, socktype, proto)
                 # if self.debuglevel > 0: print 'connect:', (host, port)
                 self.sock.connect(sa)
-            except socket.error, msg:
+            except socket.error(msg):
                 # if self.debuglevel > 0: print 'connect fail:', (host, port)
                 self.close()
                 continue
             break
         if not self.sock:
-            raise socket.error, msg
+            raise socket.error(msg)
 
     def close(self):
         if self.sock:
@@ -82,7 +82,7 @@ class gpscommon:
             sys.stderr.write("poll: reading from daemon...\n")
         eol = self.linebuffer.find('\n')
         if eol == -1:
-            frag = self.sock.recv(4096)
+            frag = self.sock.recv(4096).decode('ascii')
             self.linebuffer += frag
             if self.verbose > 1:
                 sys.stderr.write("poll: read complete.\n")
@@ -123,7 +123,7 @@ class gpscommon:
         "Ship commands to the daemon."
         if not commands.endswith("\n"):
             commands += "\n"
-        self.sock.send(commands)
+        self.sock.send(commands.encode('ascii'))
 
 WATCH_ENABLE = 0x000001 	# enable streaming
 WATCH_DISABLE = 0x000002 	# disable watching
@@ -147,7 +147,7 @@ class gpsjson:
     def unpack(self, buf):
         try:
             self.data = dictwrapper(json.loads(buf.strip(), encoding="ascii"))
-        except ValueError, e:
+        except ValueError(e):
             raise json_error(buf, e.args[0])
         # Should be done for any other array-valued subobjects, too.
         # This particular logic can fire on SKY or RTCM2 objects.
diff --git a/gps/fake.py b/gps/fake.py
index cadd68d5..13fa542d 100644
--- a/gps/fake.py
+++ b/gps/fake.py
@@ -67,8 +67,10 @@ To allow for adding and removing clients while the test is running,
 run in threaded mode by calling the start() method.  This simply calls
 the run method in a subthread, with locking of critical regions.
 """
+from __future__ import print_function
+
 import os, sys, time, signal, pty, termios  # fcntl, array, struct
-import exceptions, threading, socket, select
+import threading, socket, select
 import gps
 import packet as sniffer
 import stat
@@ -114,9 +116,9 @@ def GetDelay(slow=False):
     return delay
 
 
-class TestLoadError(exceptions.Exception):
+class TestLoadError(BaseException):
     def __init__(self, msg):
-        exceptions.Exception.__init__(self)
+        BaseException.__init__(self)
         self.msg = msg
 
 
@@ -190,7 +192,7 @@ class TestLoad:
                 if type_latch is None:
                     type_latch = ptype
                 if self.predump:
-                    print repr(packet)
+                    print(repr(packet))
                 if not packet:
                     raise TestLoadError("zero-length packet from %s" %
                                         self.name)
@@ -209,9 +211,9 @@ class TestLoad:
             self.sentences.append("# EOF\n")
 
 
-class PacketError(exceptions.Exception):
+class PacketError(BaseException):
     def __init__(self, msg):
-        exceptions.Exception.__init__(self)
+        BaseException.__init__(self)
         self.msg = msg
 
 
@@ -421,9 +423,9 @@ class FakeUDP(FakeGPS):
         pass  # shutdown() fails on UDP
 
 
-class DaemonError(exceptions.Exception):
+class DaemonError(BaseException):
     def __init__(self, msg):
-        exceptions.Exception.__init__(self)
+        BaseException.__init__(self)
         self.msg = msg
 
     def __str__(self):
@@ -546,9 +548,9 @@ class DaemonInstance:
             self.pid = None
 
 
-class TestSessionError(exceptions.Exception):
+class TestSessionError(BaseException):
     def __init__(self, msg):
-        exceptions.Exception.__init__(self)
+        BaseException.__init__(self)
         self.msg = msg
 
 
diff --git a/gps/gps.py b/gps/gps.py
index 1a0f5524..eff96552 100755
--- a/gps/gps.py
+++ b/gps/gps.py
@@ -14,8 +14,10 @@
 # The JSON parts of this (which will be reused by any new interface)
 # now live in a different module.
 #
-from client import *
-from misc import isotime
+from __future__ import print_function
+
+from .client import *
+from .misc import isotime
 
 NaN = float('nan')
 
@@ -286,7 +288,7 @@ class gps(gpscommon, gpsdata, gpsjson):
                 if type(self.fix.time) == type(0.0):
                     self.fix.time = self.utc
                 else:
-                    self.fix.time = isotime(self.utc.encode("ascii"))
+                    self.fix.time = isotime(self.utc)
             self.fix.ept       = default("ept",   NaN, TIMERR_SET)
             self.fix.latitude  = default("lat",   NaN, LATLON_SET)
             self.fix.longitude = default("lon",   NaN)
@@ -372,7 +374,7 @@ if __name__ == '__main__':
         if switch == '-v':
             verbose = True
     if len(arguments) > 2:
-        print 'Usage: gps.py [-v] [host [port]]'
+        print('Usage: gps.py [-v] [host [port]]')
         sys.exit(1)
 
     opts = {"verbose": verbose}
@@ -385,9 +387,9 @@ if __name__ == '__main__':
     session.stream(WATCH_ENABLE)
     try:
         for report in session:
-            print report
+            print(report)
     except KeyboardInterrupt:
         # Avoid garble on ^C
-        print ""
+        print("")
 
 # gps.py ends here
diff --git a/gps/misc.py b/gps/misc.py
index b34f627a..5f8bc44c 100644
--- a/gps/misc.py
+++ b/gps/misc.py
@@ -55,8 +55,10 @@ def CalcRad(lat):
     return r
 
 
-def EarthDistance((lat1, lon1), (lat2, lon2)):
+def EarthDistance(c1, c2):
     "Distance in meters between two points specified in degrees."
+    (lat1, lon1) = c1
+    (lat2, lon2) = c2
     x1 = CalcRad(lat1) * math.cos(Deg2Rad(lon1)) * math.sin(Deg2Rad(90 - lat1))
     x2 = CalcRad(lat2) * math.cos(Deg2Rad(lon2)) * math.sin(Deg2Rad(90 - lat2))
     y1 = CalcRad(lat1) * math.sin(Deg2Rad(lon1)) * math.sin(Deg2Rad(90 - lat1))
@@ -75,8 +77,10 @@ def EarthDistance((lat1, lon1), (lat2, lon2)):
     return CalcRad((lat1 +lat2) / 2) * math.acos(a)
 
 
-def MeterOffset((lat1, lon1), (lat2, lon2)):
+def MeterOffset(c1, c2):
     "Return offset in meters of second arg from first."
+    (lat1, lon1) = c1
+    (lat2, lon2) = c2
     dx = EarthDistance((lat1, lon1), (lat1, lon2))
     dy = EarthDistance((lat1, lon1), (lat2, lon1))
     if lat1 < lat2:
diff --git a/gpsprof b/gpsprof
index 15374de4..63090048 100755
--- a/gpsprof
+++ b/gpsprof
@@ -1,4 +1,4 @@
-#!/usr/bin/env python2
+#!/usr/bin/env python
 #
 # This file is Copyright (c) 2010 by the GPSD project
 # BSD terms apply: see the file COPYING in the distribution root for details.
@@ -6,6 +6,7 @@
 # Collect and plot latency-profiling data from a running gpsd.
 # Requires gnuplot.
 #
+# This code runs under both Python 2 and Python 3. Preserve this property!
 import copy
 import getopt
 import gps
@@ -183,7 +184,7 @@ class spaceplot(plotter):
             # centroid is just arithmetic avg of lat,lon
             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)))
+            self.fixes.sort(key=lambda p: self.d(self.centroid, p))
             # Convert fixes to offsets from centroid in meters
             self.recentered = [gps.MeterOffset(self.centroid, fix[:2]) for fix in self.fixes]
 
@@ -219,8 +220,8 @@ class spaceplot(plotter):
         else:
             alt_avg = alt_sum / alt_num
             # Sort fixes by distance from average altitude
-            alt_fixes.sort(lambda x, y: cmp(abs(alt_avg - x), abs(alt_avg - y)))
-            alt_ep = abs(alt_fixes[len(alt_fixes) / 2] - alt_avg)
+            alt_fixes.sort(key=lambda a: abs(alt_avg - a))
+            alt_ep = abs(alt_fixes[len(alt_fixes) // 2] - alt_avg)
         if self.centroid[0] < 0:
             latstring = "%fS" % -self.centroid[0]
         elif self.centroid[0] == 0:
@@ -246,7 +247,7 @@ class spaceplot(plotter):
             fmt += 'set y2label "Meters Altitude from %f"\n' % alt_avg
             fmt += 'set ytics nomirror\n'
             fmt += 'set y2tics\n'
-        fmt += 'cep=%f\n' % self.d((0, 0), self.recentered[len(self.fixes) / 2])
+        fmt += 'cep=%f\n' % self.d((0, 0), self.recentered[len(self.fixes) // 2])
         fmt += 'cep95=%f\n' % self.d((0, 0), self.recentered[int(len(self.fixes) * 0.95)])
         fmt += 'cep99=%f\n' % self.d((0, 0), self.recentered[int(len(self.fixes) * 0.99)])
         fmt += 'set parametric\n'
diff --git a/leapsecond.py b/leapsecond.py
index e778d236..89c38661 100755
--- a/leapsecond.py
+++ b/leapsecond.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python2
+#!/usr/bin/env python
 """
 
 Usage: leapsecond.py [-v] { [-h] | [-f filename] | [-g filename] | [-H filename]
@@ -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.
 
 """
+# This code runs under both Python 2 and Python 3. Preserve this property!
 from __future__ import print_function
 
 import os, urllib, re, random, time, calendar, math, sys, signal