Added API's "from" and "to" parameters

Since the script always begins with the most recent tracks it is not very useful if one wants to get only the latest scrobbles without all the old tracks one might already have. For that the parameters "from" and "to" (in UNIX timestamp) are necessary, so I have added them as options. By default, they are empty (default=None), in which case the script works as before.
A remark for future development:
lastexport.py:132: DeprecationWarning: This method will be removed in future versions. Use 'list(elem)' or iteration over elem instead.
if trackelement.find('artist').getchildren():

lastexport.py

@@ -14,17 +14,20 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
+# Downloaded from: https://github.com/encukou/lastscrape-gui/blob/master/lastexport.py
+# Does not work with Python2
+#
 
 """
 Script for exporting tracks through audioscrobbler API.
-Usage: lastexport.py -u USER [-o OUTFILE] [-p STARTPAGE] [-s SERVER]
+Usage: lastexport.py -u USER [-o OUTFILE] [-p STARTPAGE] [-s SERVER] [-f FROMUTS] [-z TOUTS]
 """
 import pdb
 import urllib.request, urllib.error, urllib.parse, urllib.request, urllib.parse, urllib.error, sys, time, re
 import xml.etree.ElementTree as ET
 from optparse import OptionParser
 
-__version__ = '0.0.4'
+__version__ = '0.0.5'
 
 def get_options(parser):
     """ Define command line options."""
@@ -34,6 +37,10 @@ def get_options(parser):
                       help="Output file, default is exported_tracks.txt")
     parser.add_option("-p", "--page", dest="startpage", type="int", default="1",
                       help="Page to start fetching tracks from, default is 1")
+    parser.add_option("-f", "--from", dest="fromuts", type="int", default=None,
+                      help="Unix timestamp - only display scrobbles after this time, default is none")
+    parser.add_option("-z", "--to", dest="touts", type="int", default=None,
+                      help="Unix timestamp - only display scrobbles after this time, default is none")
     parser.add_option("-s", "--server", dest="server", default="last.fm",
                       help="Server to fetch track info from, default is last.fm")
     parser.add_option("-t", "--type", dest="infotype", default="scrobbles",
@@ -50,9 +57,9 @@ def get_options(parser):
     else:
         infotype = "recenttracks"
 
-    return options.username, options.outfile, options.startpage, options.server, infotype
+    return options.username, options.outfile, options.startpage, options.fromuts, options.touts, options.server, infotype
 
-def connect_server(server, username, startpage, sleep_func=time.sleep, tracktype='recenttracks'):
+def connect_server(server, username, startpage, fromuts, touts, sleep_func=time.sleep, tracktype='recenttracks'):
     """ Connect to server and get a XML page."""
     if server == "libre.fm":
         baseurl = 'http://alpha.libre.fm/2.0/?'
@@ -69,6 +76,11 @@ def connect_server(server, username, startpage, sleep_func=time.sleep, tracktype
                     user=username,
                     page=startpage,
                     limit=50)
+        if fromuts:
+            urlvars['from'] = fromuts
+        if touts:
+            urlvars['to'] = touts
+
     else:
         if server[:7] != 'http://':
             server = 'http://%s' % server
@@ -151,9 +163,9 @@ def write_tracks(tracks, outfileobj):
     for fields in tracks:
         outfileobj.write("\t".join(fields) + "\n")
 
-def get_tracks(server, username, startpage=1, sleep_func=time.sleep, tracktype='recenttracks'):
+def get_tracks(server, username, fromuts, touts, startpage=1, sleep_func=time.sleep, tracktype='recenttracks'):
     page = startpage
-    response = connect_server(server, username, page, sleep_func, tracktype)
+    response = connect_server(server, username, page, fromuts, touts, sleep_func, tracktype)
     totalpages = get_pageinfo(response, tracktype)
 
     if startpage > totalpages:
@@ -163,7 +175,7 @@ def get_tracks(server, username, startpage=1, sleep_func=time.sleep, tracktype='
         #Skip connect if on first page, already have that one stored.
 
         if page > startpage:
-            response =  connect_server(server, username, page, sleep_func, tracktype)
+            response =  connect_server(server, username, page, fromuts, touts, sleep_func, tracktype)
 
         tracklist = get_tracklist(response)
 
@@ -178,13 +190,13 @@ def get_tracks(server, username, startpage=1, sleep_func=time.sleep, tracktype='
         page += 1
         sleep_func(.5)
 
-def main(server, username, startpage, outfile, infotype='recenttracks'):
+def main(server, username, startpage, fromuts, touts, outfile, infotype='recenttracks'):
     trackdict = dict()
     page = startpage  # for case of exception
     totalpages = -1  # ditto
     n = 0
     try:
-        for page, totalpages, tracks in get_tracks(server, username, startpage, tracktype=infotype):
+        for page, totalpages, tracks in get_tracks(server, username, fromuts, touts, startpage, tracktype=infotype):
             print("Got page %s of %s.." % (page, totalpages))
             for track in tracks:
                 if infotype == 'recenttracks':
@@ -205,5 +217,5 @@ def main(server, username, startpage, outfile, infotype='recenttracks'):
 
 if __name__ == "__main__":
     parser = OptionParser()
-    username, outfile, startpage, server, infotype = get_options(parser)
-    main(server, username, startpage, outfile, infotype)
+    username, outfile, startpage, fromuts, touts, server, infotype = get_options(parser)
+    main(server, username, startpage, fromuts, touts, outfile, infotype)