Drop Python 2 support

.travis.yml

@@ -1,14 +1,9 @@
 language: python
 dist: bionic
 python:
-  - 2.7
   - 3.6
   - 3.7
   - 3.8
-matrix:
-  include:
-    - dist: trusty
-      python: 2.6
 addons:
   apt:
     packages:

doc/installation.rst

@@ -28,12 +28,11 @@ used in other environments with some modification.
 Prerequisites
 -------------
 
-* Python. The backend of the framework, which takes care of running jobs,
-  is implemented in Python. It requires Python 2.6 or later (it should
-  also work with Python 3).
+* Python 3. The backend of the framework, which takes care of running jobs,
+  is implemented in Python. (It does not work with Python 2.)
 
 * `Flask <http://flask.pocoo.org/>`_. The frontend, which handles user
-  submission of jobs and the display of results, is implemented in Python,
+  submission of jobs and the display of results, is implemented in Python 3,
   and uses the Flask microframework.
 
 * SGE. The framework expects to be run on a machine that is a submit host to a Sun GridEngine compute cluster

python/saliweb/backend/__init__.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 import subprocess
 import re
 import fcntl
@@ -8,37 +7,25 @@
 import datetime
 import shutil
 import time
-try:
-    import configparser
-except ImportError:  # python 2.6
-    import ConfigParser as configparser
+import configparser
 import traceback
 import select
 import signal
 import socket
 import logging
 import threading
-try:
-    import urllib.request as urllib2 # python 3
-except ImportError:
-    import urllib2  # python 2
-try:
-    import urlparse  # python 2
-except ImportError:
-    import urllib.parse as urlparse  # python 3
+import urllib.request
+import urllib.parse
 import saliweb.web_service
 import saliweb.backend.events
 import saliweb.backend.sge
 from saliweb.backend.events import _JobThread
-try:
-    from email.MIMEText import MIMEText  # python 2
-except ImportError:
-    from email.mime.text import MIMEText  # python 3
+from email.mime.text import MIMEText
 
 
-# Version check; we need 2.4 for subprocess, decorators, generator expressions
-if sys.version_info[0:2] < (2, 4):
-    raise ImportError("This module requires Python 2.4 or later")
+# Version check
+if sys.version_info[0:2] < (3, 6):
+    raise ImportError("This module requires Python 3.6 or later")
 
 
 class InvalidStateError(Exception):
@@ -222,19 +209,19 @@ class Config(object):
     _mailer = '/usr/sbin/sendmail'
 
     def __init__(self, fh):
-        config = configparser.SafeConfigParser()
+        config = configparser.ConfigParser()
         if not hasattr(fh, 'read'):
             self._config_dir = os.path.dirname(os.path.abspath(fh))
             with open(fh) as fp:
-                config.readfp(fp, fh)
+                config.read_file(fp, fh)
         else:
             self._config_dir = None
-            config.readfp(fh)
+            config.read_file(fh)
         self.populate(config)
 
     def populate(self, config):
         """Populate data structures using the passed `config`, which is a
-           :class:`configparser.SafeConfigParser` object.
+           :class:`configparser.ConfigParser` object.
            This can be overridden in subclasses to read additional
            service-specific information from the configuration file."""
         self._populate_database(config)
@@ -305,9 +292,9 @@ def _populate_limits(self, config):
 
     def _read_db_auth(self, end='back'):
         filename = self.database[end + 'end_config']
-        config = configparser.SafeConfigParser()
+        config = configparser.ConfigParser()
         with open(filename) as fh:
-            config.readfp(fh, filename)
+            config.read_file(fh, filename)
         for key in ('user', 'passwd'):
             self.database[key] = config.get(end + 'end_db', key)
 
@@ -1883,13 +1870,13 @@ def __init__(self, url):
 
     def get_filename(self):
         """Return the name of the file corresponding to this result."""
-        return os.path.basename(urlparse.urlparse(self.url)[2])
+        return os.path.basename(urllib.parse.urlparse(self.url)[2])
 
     def download(self, fh=None):
         """Download the result file. If `fh` is given, it should be a Python
            file-like object, to which the file is written. Otherwise, the file
            is written into the job directory with the same name."""
-        fin = urllib2.urlopen(self.url)
+        fin = urllib.request.urlopen(self.url)
         if fh is None:
             outfh = open(self.get_filename(), 'w')
         else:

python/saliweb/backend/delete_all_jobs.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 import saliweb.backend
 import sys
 

python/saliweb/backend/deljob.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 import saliweb.backend
 from optparse import OptionParser
 import sys

python/saliweb/backend/failjob.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 import saliweb.backend
 from optparse import OptionParser
 import sys

python/saliweb/backend/list_jobs.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 import saliweb.backend
 from optparse import OptionParser
 import sys

python/saliweb/backend/resubmit.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 from optparse import OptionParser
 import sys
 

python/saliweb/backend/service.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 from optparse import OptionParser
 import saliweb.backend
 import sys

python/saliweb/build/__init__.py

@@ -6,7 +6,6 @@
 
 """
 
-from __future__ import print_function
 try:
     import MySQLdb
 except ImportError as detail:

python/saliweb/frontend/__init__.py

@@ -1,10 +1,7 @@
 import flask
 from flask import url_for, Markup
 import datetime
-try:
-    import configparser
-except ImportError:
-    import ConfigParser as configparser
+import configparser
 import os
 import sys
 import re
@@ -173,10 +170,10 @@ def _read_config(app, fname):
     # Set defaults for all web services
     app.config.from_object(saliweb.frontend.config)
 
-    config = configparser.SafeConfigParser()
+    config = configparser.ConfigParser()
 
     with open(fname) as fh:
-        config.readfp(fh, fname)
+        config.read_file(fh, fname)
 
     for section in config.sections():
         prefix = '' if section == 'general' else section.upper() + '_'
@@ -187,7 +184,7 @@ def _read_config(app, fname):
     frontend_db = config.get('database', 'frontend_config')
     fname = os.path.join(config_dir, frontend_db)
     with open(fname) as fh:
-        config.readfp(fh, fname)
+        config.read_file(fh, fname)
     for name in ('user', 'passwd'):
         value = config.get('frontend_db', name)
         app.config["DATABASE_" + name.upper()] = value

python/saliweb/make_web_service.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 from optparse import OptionParser
 import string
 import random

python/saliweb/test/run-tests.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 import unittest
 import sys
 import os

python/saliweb/web_service.py

@@ -9,8 +9,6 @@
    command line interface to the services.
 """
 
-from __future__ import print_function
-
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation; either version 2 of the License, or