Merge 221493d816 into 0049c98684

This reverts commit e47dcae54e.

RNS/Interfaces/Android/RNodeInterface.py

@@ -428,7 +428,7 @@ class RNodeInterface(Interface):
             RNS.log("Invalid frequency configured for "+str(self), RNS.LOG_ERROR)
             self.validcfg = False
 
-        if (self.txpower < 0 or self.txpower > 17):
+        if (self.txpower < 0 or self.txpower > 22):
             RNS.log("Invalid TX power configured for "+str(self), RNS.LOG_ERROR)
             self.validcfg = False
 

RNS/Transport.py

@@ -482,12 +482,26 @@ class Transport:
                                 # If the link destination was previously only 1 hop
                                 # away, this likely means that it was local to one
                                 # of our interfaces, and that it roamed somewhere else.
-                                # In that case, try to discover a new path.
+                                # In that case, try to discover a new path, and mark
+                                # the old one as unresponsive.
                                 elif not path_request_throttle and Transport.hops_to(link_entry[6]) == 1:
                                     RNS.log("Trying to rediscover path for "+RNS.prettyhexrep(link_entry[6])+" since an attempted link was never established, and destination was previously local to an interface on this instance", RNS.LOG_DEBUG)
                                     path_request_conditions = True
                                     blocked_if = link_entry[4]
 
+                                    # TODO: This might result in the path re-resolution
+                                    # only being able to happen once, since new path found
+                                    # after allowing update from higher hop-count path, after
+                                    # marking old path unresponsive, might be more than 1 hop away,
+                                    # thus dealocking us into waiting for a new announce all-together.
+                                    # Is this problematic, or does it actually not matter?
+                                    # Best would be to have full support for alternative paths,
+                                    # and score them according to number of unsuccessful tries or
+                                    # similar.
+                                    if RNS.Reticulum.transport_enabled():
+                                        if hasattr(link_entry[4], "mode") and link_entry[4].mode != RNS.Interfaces.Interface.Interface.MODE_BOUNDARY:
+                                            Transport.mark_path_unresponsive(link_entry[6])
+
                                 # If the link initiator is only 1 hop away,
                                 # this likely means that network topology has
                                 # changed. In that case, we try to discover a new path,

RNS/Utilities/rnid.py

@@ -37,26 +37,48 @@ SIG_EXT = "rsg"
 ENCRYPT_EXT = "rfe"
 CHUNK_SIZE = 16*1024*1024
 
-def spin(until=None, msg=None, timeout=None):
+
+def spin(until=None, msg="", timeout=None):
     i = 0
     syms = "⢄⢂⢁⡁⡈⡐⡠"
-    if timeout != None:
+    if timeout is not None:
         timeout = time.time()+timeout
 
-    print(msg+"  ", end=" ")
-    while (timeout == None or time.time()<timeout) and not until():
+    print(msg, end="   ")
+    while (timeout is None or time.time()<timeout) and not until():
         time.sleep(0.1)
-        print(("\b\b"+syms[i]+" "), end="")
+        print(("\b\b", syms[i]), end=" ", sep="")
         sys.stdout.flush()
         i = (i+1)%len(syms)
 
-    print("\r"+" "*len(msg)+"  \r", end="")
+    print("\r", *len(msg), "\r", end="", sep="")
 
-    if timeout != None and time.time() > timeout:
+    if timeout is not None and time.time() > timeout:
         return False
     else:
         return True
 
+
+def get_keys(args: argparse.Namespace, identity) -> None:
+    """Get public or/and private keys"""
+
+    if args.base64:
+        RNS.log("Public Key  : " + base64.urlsafe_b64encode(identity.get_public_key()).decode("utf-8"))
+    elif args.base32:
+        RNS.log("Public Key  : " + base64.b32encode(identity.get_public_key()).decode("utf-8"))
+    else:
+        RNS.log("Public Key  : " + RNS.hexrep(identity.get_public_key(), delimit=False))
+    if identity.prv:
+        if args.print_private:
+            if args.base64:
+                RNS.log("Private Key : " + base64.urlsafe_b64encode(identity.get_private_key()).decode("utf-8"))
+            elif args.base32:
+                RNS.log("Private Key : " + base64.b32encode(identity.get_private_key()).decode("utf-8"))
+            else:
+                RNS.log("Private Key : " + RNS.hexrep(identity.get_private_key(), delimit=False))
+        else:
+            RNS.log("Private Key : Hidden")
+
 def main():
     try:
         parser = argparse.ArgumentParser(description="Reticulum Identity & Encryption Utility")
@@ -96,11 +118,7 @@ def main():
 
         args = parser.parse_args()
 
-        ops = 0;
-        for t in [args.encrypt, args.decrypt, args.validate, args.sign]:
-            if t:
-                ops += 1
-        
+        ops = sum(1 for t in [args.encrypt, args.decrypt, args.validate, args.sign] if t)
         if ops > 1:
             RNS.log("This utility currently only supports one of the encrypt, decrypt, sign or verify operations per invocation", RNS.LOG_ERROR)
             exit(1)
@@ -134,22 +152,8 @@ def main():
                 exit(42)
 
             RNS.log("Identity imported")
-            if args.base64:
-                RNS.log("Public Key  : "+base64.urlsafe_b64encode(identity.get_public_key()).decode("utf-8"))
-            elif args.base32:
-                RNS.log("Public Key  : "+base64.b32encode(identity.get_public_key()).decode("utf-8"))
-            else:
-                RNS.log("Public Key  : "+RNS.hexrep(identity.get_public_key(), delimit=False))
-            if identity.prv:
-                if args.print_private:
-                    if args.base64:
-                        RNS.log("Private Key : "+base64.urlsafe_b64encode(identity.get_private_key()).decode("utf-8"))
-                    elif args.base32:
-                        RNS.log("Private Key : "+base64.b32encode(identity.get_private_key()).decode("utf-8"))
-                    else:
-                        RNS.log("Private Key : "+RNS.hexrep(identity.get_private_key(), delimit=False))
-                else:
-                    RNS.log("Private Key : Hidden")
+
+            get_keys(args, identity)
 
             if args.write:
                 try:
@@ -208,7 +212,7 @@ def main():
                     destination_hash = bytes.fromhex(identity_str)
                     identity = RNS.Identity.recall(destination_hash)
 
-                    if identity == None:
+                    if identity is None:
                         if not args.request:
                             RNS.log("Could not recall Identity for "+RNS.prettyhexrep(destination_hash)+".", RNS.LOG_ERROR)
                             RNS.log("You can query the network for unknown Identities with the -R option.", RNS.LOG_ERROR)
@@ -216,7 +220,7 @@ def main():
                         else:
                             RNS.Transport.request_path(destination_hash)
                             def spincheck():
-                                return RNS.Identity.recall(destination_hash) != None
+                                return RNS.Identity.recall(destination_hash) is not None
                             spin(spincheck, "Requesting unknown Identity for "+RNS.prettyhexrep(destination_hash), args.t)
 
                             if not spincheck():
@@ -224,17 +228,15 @@ def main():
                                 exit(6)
                             else:
                                 identity = RNS.Identity.recall(destination_hash)
-                                RNS.log("Received Identity "+str(identity)+" for destination "+RNS.prettyhexrep(destination_hash)+" from the network")
+                                RNS.log(" ".join(["Received Identity", str(identity), "for destination", RNS.prettyhexrep(destination_hash), "from the network"]))
 
                     else:
-                        RNS.log("Recalled Identity "+str(identity)+" for destination "+RNS.prettyhexrep(destination_hash))
-
+                        RNS.log(" ".join(["Recalled Identity", str(identity), "for destination", RNS.prettyhexrep(destination_hash)]))
 
                 except Exception as e:
                     RNS.log("Invalid hexadecimal hash provided", RNS.LOG_ERROR)
                     exit(7)
 
-                
             else:
                 # Try loading Identity from file
                 if not os.path.isfile(identity_str):
@@ -243,13 +245,13 @@ def main():
                 else:
                     try:
                         identity = RNS.Identity.from_file(identity_str)
-                        RNS.log("Loaded Identity "+str(identity)+" from "+str(identity_str))
+                        RNS.log(" ".join(["Loaded Identity", str(identity), "from", str(identity_str)]))
 
                     except Exception as e:
                         RNS.log("Could not decode Identity from specified file")
                         exit(9)
 
-            if identity != None:
+            if identity is not None:
                 if args.hash:
                     try:
                         aspects = args.hash.split(".")
@@ -259,9 +261,9 @@ def main():
                         else:
                             app_name = aspects[0]
                             aspects = aspects[1:]
-                            if identity.pub != None:
+                            if identity.pub is not None:
                                 destination = RNS.Destination(identity, RNS.Destination.OUT, RNS.Destination.SINGLE, app_name, *aspects)
-                                RNS.log("The "+str(args.hash)+" destination for this Identity is "+RNS.prettyhexrep(destination.hash))
+                                RNS.log(" ".join(["The", str(args.hash), "destination for this Identity is", RNS.prettyhexrep(destination.hash)]))
                                 RNS.log("The full destination specifier is "+str(destination))
                                 time.sleep(0.25)
                                 exit(0)
@@ -282,7 +284,7 @@ def main():
                         else:
                             app_name = aspects[0]
                             aspects = aspects[1:]
-                            if identity.prv != None:
+                            if identity.prv is not None:
                                 destination = RNS.Destination(identity, RNS.Destination.IN, RNS.Destination.SINGLE, app_name, *aspects)
                                 RNS.log("Created destination "+str(destination))
                                 RNS.log("Announcing destination "+RNS.prettyhexrep(destination.hash))
@@ -291,7 +293,7 @@ def main():
                                 exit(0)
                             else:
                                 destination = RNS.Destination(identity, RNS.Destination.OUT, RNS.Destination.SINGLE, app_name, *aspects)
-                                RNS.log("The "+str(args.announce)+" destination for this Identity is "+RNS.prettyhexrep(destination.hash))
+                                RNS.log(" ".join(["The", str(args.announce), "destination for this Identity is", RNS.prettyhexrep(destination.hash)]))
                                 RNS.log("The full destination specifier is "+str(destination))
                                 RNS.log("Cannot announce this destination, since the private key is not held")
                                 time.sleep(0.25)
@@ -303,22 +305,7 @@ def main():
                     exit(0)
 
                 if args.print_identity:
-                    if args.base64:
-                        RNS.log("Public Key  : "+base64.urlsafe_b64encode(identity.get_public_key()).decode("utf-8"))
-                    elif args.base32:
-                        RNS.log("Public Key  : "+base64.b32encode(identity.get_public_key()).decode("utf-8"))
-                    else:
-                        RNS.log("Public Key  : "+RNS.hexrep(identity.get_public_key(), delimit=False))
-                    if identity.prv:
-                        if args.print_private:
-                            if args.base64:
-                                RNS.log("Private Key : "+base64.urlsafe_b64encode(identity.get_private_key()).decode("utf-8"))
-                            elif args.base32:
-                                RNS.log("Private Key : "+base64.b32encode(identity.get_private_key()).decode("utf-8"))
-                            else:
-                                RNS.log("Private Key : "+RNS.hexrep(identity.get_private_key(), delimit=False))
-                        else:
-                            RNS.log("Private Key : Hidden")
+                    get_keys(args, identity)
                     exit(0)
 
                 if args.export:
@@ -373,7 +360,7 @@ def main():
                 if args.decrypt and not args.write and not args.stdout and args.read and args.read.lower().endswith("."+ENCRYPT_EXT):
                     args.write = str(args.read).replace("."+ENCRYPT_EXT, "")
 
-                if args.sign and identity.prv == None:
+                if args.sign and identity.prv is None:
                     RNS.log("Specified Identity does not hold a private key. Cannot sign.", RNS.LOG_ERROR)
                     exit(14)
 
@@ -399,7 +386,7 @@ def main():
                 #     data_output = sys.stdout
 
                 if args.sign:
-                    if identity.prv == None:
+                    if identity.prv is None:
                         RNS.log("Specified Identity does not hold a private key. Cannot sign.", RNS.LOG_ERROR)
                         exit(16)
 
@@ -423,7 +410,7 @@ def main():
 
                             if not args.stdout:
                                 if args.read:
-                                    RNS.log("File "+str(args.read)+" signed with "+str(identity)+" to "+str(args.write))
+                                    RNS.log(" ".join([ "File", str(args.read), "signed with", str(identity), "to", str(args.write) ]))
                                     exit(0)
 
                         except Exception as e:
@@ -457,18 +444,17 @@ def main():
                                 RNS.log("The contained exception was: "+str(e), RNS.LOG_ERROR)
                                 exit(21)
 
-
                             validated = identity.validate(sig_input.read(), data_input.read())
                             sig_input.close()
                             data_input.close()
 
                             if not validated:
                                 if not args.stdout:
-                                    RNS.log("Signature "+str(args.validate)+" for file "+str(args.read)+" is invalid", RNS.LOG_ERROR)
+                                    RNS.log(" ".join(["Signature", str(args.validate), "for file", str(args.read), "is invalid"]), RNS.LOG_ERROR)
                                 exit(22)
                             else:
                                 if not args.stdout:
-                                    RNS.log("Signature "+str(args.validate)+" for file "+str(args.read)+" made by Identity "+str(identity)+" is valid")
+                                    RNS.log(" ".join(["Signature", str(args.validate), "for file", str(args.read), "made by Identity", str(identity), "is valid"]))
                                 exit(0)
 
                         except Exception as e:
@@ -511,7 +497,7 @@ def main():
                             data_input.close()
                             if not args.stdout:
                                 if args.read:
-                                    RNS.log("File "+str(args.read)+" encrypted for "+str(identity)+" to "+str(args.write))
+                                    RNS.log(" ".join(["File", str(args.read), "encrypted for", str(identity), "to", str(args.write)]))
                                     exit(0)
 
                         except Exception as e:
@@ -529,7 +515,7 @@ def main():
                             exit(26)
 
                 if args.decrypt:
-                    if identity.prv == None:
+                    if identity.prv is None:
                         RNS.log("Specified Identity does not hold a private key. Cannot decrypt.", RNS.LOG_ERROR)
                         exit(27)
 
@@ -544,7 +530,7 @@ def main():
                             exit(29)
 
                         if not args.stdout:
-                            RNS.log("Decrypting "+str(args.read)+"...")
+                            RNS.log("".join(["Decrypting ", str(args.read), "..."]))
 
                         try:
                             more_data = True
@@ -552,7 +538,7 @@ def main():
                                 chunk = data_input.read(CHUNK_SIZE)
                                 if chunk:
                                     plaintext = identity.decrypt(chunk)
-                                    if plaintext == None:
+                                    if plaintext is None:
                                         if not args.stdout:
                                             RNS.log("Data could not be decrypted with the specified Identity")
                                         exit(30)
@@ -564,7 +550,7 @@ def main():
                             data_input.close()
                             if not args.stdout:
                                 if args.read:
-                                    RNS.log("File "+str(args.read)+" decrypted with "+str(identity)+" to "+str(args.write))
+                                    RNS.log(" ".join(["File", str(args.read), "decrypted with", str(identity), "to", str(args.write)]))
                                     exit(0)
 
                         except Exception as e:
@@ -581,20 +567,10 @@ def main():
                                 pass
                             exit(31)
 
-            if True:
-                pass
-
-            elif False:
-                pass
-
-            else:
-                print("")
-                parser.print_help()
-                print("")
-
     except KeyboardInterrupt:
         print("")
         exit(255)
 
+
 if __name__ == "__main__":
     main()

RNS/Utilities/rnir.py

@@ -24,13 +24,12 @@
 
 import RNS
 import argparse
-import time
 
 from RNS._version import __version__
 
 
-def program_setup(configdir, verbosity = 0, quietness = 0, service = False):
-    targetverbosity = verbosity-quietness
+def program_setup(configdir, verbosity=0, quietness=0, service=False):
+    targetverbosity = verbosity - quietness
 
     if service:
         targetlogdest = RNS.LOG_FILE
@@ -38,9 +37,10 @@ def program_setup(configdir, verbosity = 0, quietness = 0, service = False):
     else:
         targetlogdest = RNS.LOG_STDOUT
 
-    reticulum = RNS.Reticulum(configdir=configdir, verbosity=targetverbosity, logdest=targetlogdest)
+    RNS.Reticulum(configdir=configdir, verbosity=targetverbosity, logdest=targetlogdest)
     exit(0)
 
+
 def main():
     try:
         parser = argparse.ArgumentParser(description="Reticulum Distributed Identity Resolver")
@@ -49,24 +49,23 @@ def main():
         parser.add_argument('-q', '--quiet', action='count', default=0)
         parser.add_argument("--exampleconfig", action='store_true', default=False, help="print verbose configuration example to stdout and exit")
         parser.add_argument("--version", action="version", version="ir {version}".format(version=__version__))
-        
         args = parser.parse_args()
 
         if args.exampleconfig:
             print(__example_rns_config__)
             exit()
 
+        configarg = None
         if args.config:
             configarg = args.config
-        else:
-            configarg = None
 
-        program_setup(configdir = configarg, verbosity=args.verbose, quietness=args.quiet)
+        program_setup(configdir=configarg, verbosity=args.verbose, quietness=args.quiet)
 
     except KeyboardInterrupt:
         print("")
         exit()
 
+
 __example_rns_config__ = '''# This is an example Identity Resolver file.
 '''
 

RNS/Utilities/rnstatus.py

@@ -27,13 +27,14 @@ import argparse
 
 from RNS._version import __version__
 
+
 def size_str(num, suffix='B'):
-    units = ['','K','M','G','T','P','E','Z']
+    units = ['', 'K', 'M', 'G', 'T', 'P', 'E', 'Z']
     last_unit = 'Y'
 
     if suffix == 'b':
         num *= 8
-        units = ['','K','M','G','T','P','E','Z']
+        units = ['', 'K', 'M', 'G', 'T', 'P', 'E', 'Z']
         last_unit = 'Y'
 
     for unit in units:
@@ -46,6 +47,14 @@ def size_str(num, suffix='B'):
 
     return "%.2f%s%s" % (num, last_unit, suffix)
 
+
+def convert_bytes_to_hex(value_obj):
+    if isinstance(value_obj, bytes):
+        return RNS.hexrep(value_obj, delimit=False)
+    elif isinstance(value_obj, dict):
+        return {key: convert_bytes_to_hex(value) for key, value in value_obj.items()}
+    return value_obj
+
 def program_setup(configdir, dispall=False, verbosity=0, name_filter=None, json=False, astats=False, sorting=None, sort_reverse=False):
     reticulum = RNS.Reticulum(configdir = configdir, loglevel = 3+verbosity)
 
@@ -55,44 +64,37 @@ def program_setup(configdir, dispall=False, verbosity=0, name_filter=None, json=
     except Exception as e:
         pass
 
-    if stats != None:
+    if stats is None:
+        print("Could not get RNS status")
+        return
+
     if json:
         import json
-            for s in stats:
-                if isinstance(stats[s], bytes):
-                    stats[s] = RNS.hexrep(stats[s], delimit=False)
-
-                if isinstance(stats[s], dict):
-                    for i in stats[s]:
-                        if isinstance(i, dict):
-                            for k in i:
-                                if isinstance(i[k], bytes):
-                                    i[k] = RNS.hexrep(i[k], delimit=False)
-
+        for s, value in stats.items():
+            stats[s] = convert_bytes_to_hex(value)
         print(json.dumps(stats))
         exit()
 
     interfaces = stats["interfaces"]
-        if sorting != None and isinstance(sorting, str):
+    if sorting is not None and isinstance(sorting, str):
         sorting = sorting.lower()
         if sorting == "rate" or sorting == "bitrate":
             interfaces.sort(key=lambda i: i["bitrate"], reverse=not sort_reverse)
-            if sorting == "rx":
+        elif sorting == "rx":
             interfaces.sort(key=lambda i: i["rxb"], reverse=not sort_reverse)
-            if sorting == "tx":
+        elif sorting == "tx":
             interfaces.sort(key=lambda i: i["txb"], reverse=not sort_reverse)
-            if sorting == "traffic":
+        elif sorting == "traffic":
             interfaces.sort(key=lambda i: i["rxb"]+i["txb"], reverse=not sort_reverse)
-            if sorting == "announces" or sorting == "announce":
+        elif sorting == "announces" or sorting == "announce":
             interfaces.sort(key=lambda i: i["incoming_announce_frequency"]+i["outgoing_announce_frequency"], reverse=not sort_reverse)
-            if sorting == "arx":
+        elif sorting == "arx":
             interfaces.sort(key=lambda i: i["incoming_announce_frequency"], reverse=not sort_reverse)
-            if sorting == "atx":
+        elif sorting == "atx":
             interfaces.sort(key=lambda i: i["outgoing_announce_frequency"], reverse=not sort_reverse)
-            if sorting == "held":
+        elif sorting == "held":
             interfaces.sort(key=lambda i: i["held_announces"], reverse=not sort_reverse)
 
-            
     for ifstat in interfaces:
         name = ifstat["name"]
 
@@ -125,8 +127,7 @@ def program_setup(configdir, dispall=False, verbosity=0, name_filter=None, json=
                     else:
                         modestr = "Full"
 
-
-                        if ifstat["clients"] != None:
+                    if ifstat["clients"] is not None:
                         clients = ifstat["clients"]
                         if name.startswith("Shared Instance["):
                             cnum = max(clients-1,0)
@@ -216,8 +217,6 @@ def program_setup(configdir, dispall=False, verbosity=0, name_filter=None, json=
 
     print("")
 
-    else:
-        print("Could not get RNS status")
 
 def main():
     try:
@@ -292,6 +291,7 @@ def main():
         print("")
         exit()
 
+
 def speed_str(num, suffix='bps'):
     units = ['','k','M','G','T','P','E','Z']
     last_unit = 'Y'
@@ -308,5 +308,6 @@ def speed_str(num, suffix='bps'):
 
     return "%.2f %s%s" % (num, last_unit, suffix)
 
+
 if __name__ == "__main__":
     main()

RNS/Utilities/rnx.py

@@ -28,7 +28,7 @@ import argparse
 import shlex
 import time
 import sys
-import tty
+# import tty # Commented this because commented lines below use it
 import os
 
 from RNS._version import __version__
@@ -39,9 +39,10 @@ reticulum = None
 allow_all = False
 allowed_identity_hashes = []
 
+
 def prepare_identity(identity_path):
     global identity
-    if identity_path == None:
+    if identity_path is None:
         identity_path = RNS.Reticulum.identitypath+"/"+APP_NAME
 
     if os.path.isfile(identity_path):
@@ -52,6 +53,7 @@ def prepare_identity(identity_path):
         identity = RNS.Identity()
         identity.to_file(identity_path)
 
+
 def listen(configdir, identitypath = None, verbosity = 0, quietness = 0, allowed = [], print_identity = False, disable_auth = None, disable_announce=False):
     global identity, allow_all, allowed_identity_hashes, reticulum
 
@@ -69,7 +71,7 @@ def listen(configdir, identitypath = None, verbosity = 0, quietness = 0, allowed
     if disable_auth:
         allow_all = True
     else:
-        if allowed != None:
+        if allowed is not None:
             for a in allowed:
                 try:
                     dest_len = (RNS.Reticulum.TRUNCATED_HASHLENGTH//8)*2
@@ -297,6 +299,7 @@ def remote_execution_progress(request_receipt):
 link = None
 listener_destination = None
 remote_exec_grace = 2.0
+
 def execute(configdir, identitypath = None, verbosity = 0, quietness = 0, detailed = False, mirror = False, noid = False, destination = None, command = None, stdin = None, stdoutl = None, stderrl = None, timeout = RNS.Transport.PATH_REQUEST_TIMEOUT, result_timeout = None, interactive = False):
     global identity, reticulum, link, listener_destination, remote_exec_grace
 
@@ -548,7 +551,6 @@ def main():
         parser.add_argument("--stdout", action='store', default=None, help="max size in bytes of returned stdout", type=int)
         parser.add_argument("--stderr", action='store', default=None, help="max size in bytes of returned stderr", type=int)
         parser.add_argument("--version", action="version", version="rnx {version}".format(version=__version__))
-        
         args = parser.parse_args()
 
         if args.listen or args.print_identity:
@@ -668,6 +670,7 @@ def size_str(num, suffix='B'):
 
     return "%.2f%s%s" % (num, last_unit, suffix)
 
+
 def pretty_time(time, verbose=False):
     days = int(time // (24 * 3600))
     time = time % (24 * 3600)
@@ -684,31 +687,24 @@ def pretty_time(time, verbose=False):
 
     components = []
     if days > 0:
-        components.append(str(days)+" day"+sd if verbose else str(days)+"d")
+        components.append("".join([str(days), " day", sd if verbose else str(days), "d"]))
 
     if hours > 0:
-        components.append(str(hours)+" hour"+sh if verbose else str(hours)+"h")
+        components.append("".join([str(hours), " hour", sh if verbose else str(hours), "h"]))
 
     if minutes > 0:
-        components.append(str(minutes)+" minute"+sm if verbose else str(minutes)+"m")
+        components.append("".join([str(minutes), " minute", sm if verbose else str(minutes), "m"]))
 
     if seconds > 0:
-        components.append(str(seconds)+" second"+ss if verbose else str(seconds)+"s")
+        components.append("".join([str(seconds), " second", ss if verbose else str(seconds), "s"]))
 
-    i = 0
-    tstr = ""
-    for c in components:
-        i += 1
-        if i == 1:
-            pass
-        elif i < len(components):
-            tstr += ", "
-        elif i == len(components):
-            tstr += " and "
+    if len(components) > 1:
+        time_string = "".join([", ".join(components[:-1]), " and ", components[-1]])
+    else:
+        time_string = components[0] if components else ""
 
-        tstr += c
+    return time_string
 
-    return tstr
 
 if __name__ == "__main__":
     main()