Merge ~bdrung/ddeb-retriever/+git/main:pylint into ddeb-retriever:main

[Benjamin Drung]

This merge request contains some fixes/improvement for things that pylint or other linters complain about.

1. fix: Iterate over apt_pkg.TagFile

pylint complains about E1136: Value 'parser.section' is unsubscriptable
(unsubscriptable-object). `apt_pkg.TagFile` claims to be an iterator
over `apt_pkg.TagSection`.

So iterate over `apt_pkg.TagFile` for the sections instead of calling
`step()` and accessing the `section` property.

This change was tested to also work on Ubuntu 16.04 "xenial" with
Python 3.5.2 and python3-apt 1.1.0~beta1ubuntu0.16.04.12.

2. Use `functools.cache` for `_get_lp()` to avoid using a global variable
and make the code more readable.

3. refactor: Mark unused variables as such

4. fix: Use lazy % formatting in logging functions

5. Use `timestamp()` method of datetime instead of calculating it manually.

Unmerged commits

6eb54c2... by Benjamin Drung on 2023-02-09

refactor: Use datetime.timestamp()

Use `timestamp()` method of datetime instead of calculating it manually.

Signed-off-by: Benjamin Drung <email address hidden>

f47a5a5... by Benjamin Drung on 2023-02-09

fix: Use lazy % formatting in logging functions

Signed-off-by: Benjamin Drung <email address hidden>

608b211... by Benjamin Drung on 2023-02-09

refactor: Mark unused variables as such

Name unused variables `_` to indicate to pylint and other linters that
these variables are not used.

Signed-off-by: Benjamin Drung <email address hidden>

8639da0... by Benjamin Drung on 2023-02-09

refactor: Use functools.cache for _get_lp()

Use `functools.cache` for `_get_lp()` to avoid using a global variable
and make the code more readable.

Signed-off-by: Benjamin Drung <email address hidden>

e207297... by Benjamin Drung on 2023-02-09

fix: Iterate over apt_pkg.TagFile

pylint complains about E1136: Value 'parser.section' is unsubscriptable
(unsubscriptable-object). `apt_pkg.TagFile` claims to be an iterator
over `apt_pkg.TagSection`.

So iterate over `apt_pkg.TagFile` for the sections instead of calling
`step()` and accessing the `section` property.

This change was tested to also work on Ubuntu 16.04 "xenial" with
Python 3.5.2 and python3-apt 1.1.0~beta1ubuntu0.16.04.12.

Signed-off-by: Benjamin Drung <email address hidden>

diff --git a/archive_tools.py b/archive_tools.py
index c8cf1aa..ecfb57f 100644
--- a/archive_tools.py
+++ b/archive_tools.py
@@ -66,13 +66,13 @@ def debcontrol_map(url, map_key='Package'):
 
     map = {}
     parser = apt_pkg.TagFile(tagfile)
-    while parser.step():
+    for section in parser:
         pkg = {}
-        for key in parser.section.keys():
+        for key in section.keys():
             if key != map_key:
-                pkg[key] = parser.section.get(key)
+                pkg[key] = section.get(key)
         if pkg:
-            map[parser.section.get(map_key)] = pkg
+            map[section.get(map_key)] = pkg
     tagfile.close()
     return map
 
@@ -156,9 +156,9 @@ def debcontrol_dominate(infile, outfile, group_by='Package',
     '''
     max = {}  # group_by -> (sort_key_value, text)
     parser = apt_pkg.TagFile(infile)
-    while parser.step():
-        if cmp(max.get(parser.section[group_by], ('', ''))[0], parser.section[sort_key]) < 0:
-            max[parser.section[group_by]] = (parser.section[sort_key], str(parser.section))
+    for section in parser:
+        if cmp(max.get(section[group_by], ('', ''))[0], section[sort_key]) < 0:
+            max[section[group_by]] = (section[sort_key], str(section))
 
     ks = sorted(max)
     first = True
@@ -292,7 +292,7 @@ Tree "dists/%s" {
                     listfile = open(os.path.join('lists', '%s-%s' % (component, arch)), 'w')
                     for f in glob.glob(os.path.join(pooldir, '*/*/*%s%s' % (arch, ext))):
                         try:
-                            (pkg, ver, suffix) = os.path.basename(f).split('_')
+                            (pkg, ver, _) = os.path.basename(f).split('_')
                         except ValueError:
                             logging.warning('Cannot split file name %s, unknown format; ignoring', f)
                             continue
@@ -350,8 +350,8 @@ def _packages_files(path, files):
 
     with open(path) as f:
         parser = apt_pkg.TagFile(f)
-    while parser.step():
-        f = parser.section['Filename']
+    for section in parser:
+        f = section['Filename']
         if f.startswith('./'):
             f = f[2:]
         files.add(f)
@@ -363,9 +363,9 @@ def _sources_files(path, files):
 
     with open(path) as f:
         parser = apt_pkg.TagFile(f)
-    while parser.step():
-        d = parser.section.get('Directory')
-        for l in parser.section['Files'].splitlines():
+    for section in parser:
+        d = section.get('Directory')
+        for l in section['Files'].splitlines():
             fields = l.split()
             assert len(fields) == 3
             if d:
@@ -390,7 +390,7 @@ def archive_cleanup(archive_root, keep_days=0):
             distroot = '.'
 
         indexed_files = set([])
-        for root, dirs, files in os.walk(distroot):
+        for root, _, files in os.walk(distroot):
             if root == '.':
                 root = ''
             elif root.startswith('./'):
@@ -424,7 +424,7 @@ def archive_cleanup(archive_root, keep_days=0):
         poolroot = 'pool'
         if not os.path.isdir(poolroot):
             poolroot = '.'
-        for root, dirs, files in os.walk(poolroot):
+        for root, _, files in os.walk(poolroot):
             if root == '.':
                 root = ''
             if root.startswith('./'):
@@ -475,7 +475,7 @@ def archive_dominate(archive_root, keep_days=0):
     if not os.path.isdir(distroot):
         distroot = archive_root
 
-    for root, dirs, files in os.walk(distroot):
+    for root, _, files in os.walk(distroot):
         if 'Packages' in files:
             path = os.path.join(root, 'Packages')
             with open(path) as old, open(path + '.new', 'w') as new:
@@ -751,7 +751,7 @@ def _find_files(dir, strip_prefix=None):
     else:
         plen = 0
     result = set([])
-    for root, dirs, files in os.walk(dir):
+    for root, _, files in os.walk(dir):
         for f in files:
             result.add(os.path.join(root, f)[plen:])
     return result
diff --git a/ddeb_retriever.py b/ddeb_retriever.py
index 2f1ac4d..5bc38b0 100644
--- a/ddeb_retriever.py
+++ b/ddeb_retriever.py
@@ -79,7 +79,7 @@ def install_from_librarian(pub, url, ddeb_archive_root):
     '''
     ddeb = urllib.parse.unquote(os.path.basename(url))
     try:
-        (dbgsymname, version, arch) = ddeb.split('_')
+        (dbgsymname, _, arch) = ddeb.split('_')
         assert arch.endswith('.ddeb')
         (arch, _) = arch.split('.')
         assert dbgsymname.endswith('-dbgsym')
@@ -163,7 +163,7 @@ def main(argv=None):
         # order during long transactions.
         real_threshold = lp_threshold - datetime.timedelta(hours=1)
         logging.info(
-            'Retrieving Launchpad publications since %s' % real_threshold)
+            'Retrieving Launchpad publications since %s', real_threshold)
     else:
         real_threshold = None
         logging.info('Retrieving all Launchpad publications')
@@ -217,8 +217,8 @@ def main(argv=None):
     installed_pockets = set()
     for i, pub in enumerate(debug_pubs):
         logging.info(
-            'Installing %d/%d: %s' %
-            (i + 1, len(debug_pubs), pub.display_name))
+            'Installing %d/%d: %s',
+            i + 1, len(debug_pubs), pub.display_name)
         already_present = False
         pub_installed = False
         if pub.binary_package_name in ddeb_map:
@@ -239,8 +239,7 @@ def main(argv=None):
             installed_pockets.add(get_suite_for_publication(pub))
 
     if latest_date_created is not None:
-        epoch = datetime.datetime.fromtimestamp(0, tz=UTC)
-        new_threshold = (latest_date_created - epoch).total_seconds()
+        new_threshold = latest_date_created.timestamp()
         with open(lp_threshold_path, 'w') as lp_threshold_file:
             lp_threshold_file.write("%d\n" % new_threshold)
 
diff --git a/lpinfo.py b/lpinfo.py
index c5410b8..841b75a 100644
--- a/lpinfo.py
+++ b/lpinfo.py
@@ -1,18 +1,17 @@
+import functools
 import logging
 import os
 
 from launchpadlib.launchpad import Launchpad
 
-lp = None
-
 
[e-mail]
 def _get_lp():
-    global lp
-    if lp is None:
-        lp = Launchpad.login_anonymously(
-            'ddeb-retriever',
-            os.environ.get('LAUNCHPAD_INSTANCE', 'production'),
-            version='devel')
+    return Launchpad.login_anonymously(
+        'ddeb-retriever',
+        os.environ.get('LAUNCHPAD_INSTANCE', 'production'),
+        version='devel'
+    )
 
 
 def get_series(distribution):
@@ -20,7 +19,7 @@ def get_series(distribution):
 
     Return name -> (components, architectures)
     '''
-    _get_lp()
+    lp = _get_lp()
     info = {}
     for s in lp.distributions[distribution].series:
         # FIXME: disco is still marked as supported in LP, but EOL
@@ -38,7 +37,7 @@ def get_series(distribution):
 def get_buildds():
     '''Return list of available buildds'''
 
-    _get_lp()
+    lp = _get_lp()
     buildds = []
 
     for builder in lp.builders:
@@ -55,7 +54,7 @@ def get_buildds():
 def get_binary_publications(distribution, created_since_date=None):
     '''Get recently-published binaries for the given distribution'''
 
-    _get_lp()
+    lp = _get_lp()
     archive = lp.distributions[distribution].main_archive
     # It's important to omit the status filter here, even if we later decide
     # that we only care about the Published status (although at the moment