Update bin/jwt file to be Python 3 compatible.

Only tested on Python 2.7.5 and Python 3.3.3 to generate and verify
tokens.

Author: ajkavanagh

bin/jwt

@@ -1,4 +1,8 @@
 #!/usr/bin/env python
+
+from __future__ import print_function
+from __future__ import unicode_literals
+
 import optparse
 import jwt
 import sys
@@ -8,27 +12,29 @@ import time
 __prog__ = 'jwt'
 __version__ = '0.1'
 
+
 def fix_optionparser_whitespace(input):
     """Hacks around whitespace Nazi-ism in OptionParser"""
     newline = ' ' * 80
     doublespace = '\033[8m.\033[0m' * 2
     return input.replace('  ', doublespace).replace('\n', newline)
 
+
 def main():
     """Encodes or decodes JSON Web Tokens based on input
-  
+
 Decoding examples:
-  
+
   %prog --key=secret json.web.token
   %prog --no-verify json.web.token
-  
-Encoding requires the key option and takes space separated key/value pairs 
+
+Encoding requires the key option and takes space separated key/value pairs
 separated by equals (=) as input. Examples:
-  
+
   %prog --key=secret iss=me exp=1302049071
   %prog --key=secret foo=bar exp=+10
-  
-The exp key is special and can take an offset to current Unix time. 
+
+The exp key is special and can take an offset to current Unix time.
 """
     p = optparse.OptionParser(description=fix_optionparser_whitespace(main.__doc__),
                                 prog=__prog__,
@@ -40,7 +46,7 @@ The exp key is special and can take an offset to current Unix time.
                     help='set the secret key to sign with')
     p.add_option('--alg', dest='algorithm', metavar='ALG', default='HS256',
                     help='set crypto algorithm to sign with. default=HS256')
-    
+
     options, arguments = p.parse_args()
     if len(arguments) > 0 or not sys.stdin.isatty():
         # Try to decode
@@ -49,22 +55,23 @@ The exp key is special and can take an offset to current Unix time.
                 token = sys.stdin.read()
             else:
                 token = arguments[0]
+            token = token.encode('utf-8')
             valid_jwt = jwt.header(token)
             if valid_jwt:
                 try:
-                    print json.dumps(jwt.decode(token, key=options.key, verify=options.verify))
+                    print(json.dumps(jwt.decode(token, key=options.key, verify=options.verify)))
                     sys.exit(0)
-                except jwt.DecodeError, e:
-                    print e
+                except jwt.DecodeError as e:
+                    print(e)
                     sys.exit(1)
         except jwt.DecodeError:
             pass
-        
+
         # Try to encode
         if options.key is None:
-            print "Key is required when encoding. See --help for usage."
+            print("Key is required when encoding. See --help for usage.")
             sys.exit(1)
-        
+
         # Build payload object to encode
         payload = {}
         for arg in arguments:
@@ -88,17 +95,17 @@ The exp key is special and can take an offset to current Unix time.
                     v = constants[v]
                 payload[k] = v
             except ValueError:
-                print "Invalid encoding input at %s" % arg
+                print("Invalid encoding input at {}".format(arg))
                 sys.exit(1)
-        
+
         try:
-            print jwt.encode(payload, key=options.key, algorithm=options.algorithm)
+            print(jwt.encode(payload, key=options.key, algorithm=options.algorithm))
             sys.exit(0)
-        except Exception, e:
-            print e
+        except Exception as e:
+            print(e)
             sys.exit(1)
     else:
         p.print_help()
 
 if __name__ == '__main__':
-     main()
+     main()