[postprocessor:zip] defer zip file creation (fixes #968)

don't try to create zip files on postprocessor construction,
wait until directory creation during file download,

CHANGELOG.md

@@ -1,5 +1,7 @@
 # Changelog
 
+## Unreleased
+
 ## 1.14.5 - 2020-08-30
 ### Additions
 - [aryion] add username/password support ([#960](https://github.com/mikf/gallery-dl/issues/960))

gallery_dl/postprocessor/zip.py

@@ -33,23 +33,23 @@ class ZipPP(PostProcessor):
                 algorithm)
             algorithm = "store"
 
+        self.zfile = None
         self.path = job.pathfmt.realdirectory
-        args = (self.path[:-1] + ext, "a",
+        self.args = (self.path[:-1] + ext, "a",
                      self.COMPRESSION_ALGORITHMS[algorithm], True)
 
         if options.get("mode") == "safe":
             self.run = self._write_safe
-            self.zfile = None
-            self.args = args
         else:
             self.run = self._write
-            self.zfile = zipfile.ZipFile(*args)
 
     def _write(self, pathfmt, zfile=None):
         # 'NameToInfo' is not officially documented, but it's available
         # for all supported Python versions and using it directly is a lot
         # faster than calling getinfo()
         if zfile is None:
+            if self.zfile is None:
+                self.zfile = zipfile.ZipFile(*self.args)
             zfile = self.zfile
         if pathfmt.filename not in zfile.NameToInfo:
             zfile.write(pathfmt.temppath, pathfmt.filename)

gallery_dl/version.py

@@ -6,4 +6,4 @@
 # it under the terms of the GNU General Public License version 2 as
 # published by the Free Software Foundation.
 
-__version__ = "1.14.5"
+__version__ = "1.15.0-dev"

test/test_postprocessor.py

@@ -342,9 +342,20 @@ class ZipTest(BasePostprocessorTest):
         self.assertEqual(pp.path, self.pathfmt.realdirectory)
         self.assertEqual(pp.run, pp._write)
         self.assertEqual(pp.delete, True)
-        self.assertFalse(hasattr(pp, "args"))
+        self.assertEqual(pp.args, (
-        self.assertEqual(pp.zfile.compression, zipfile.ZIP_STORED)
+            pp.path[:-1] + ".zip", "a", zipfile.ZIP_STORED, True,
-        self.assertTrue(pp.zfile.filename.endswith("/test.zip"))
+        ))
+        self.assertTrue(pp.args[0].endswith("/test.zip"))
+
+    def test_zip_safe(self):
+        pp = self._create({"mode": "safe"})
+        self.assertEqual(pp.path, self.pathfmt.realdirectory)
+        self.assertEqual(pp.run, pp._write_safe)
+        self.assertEqual(pp.delete, True)
+        self.assertEqual(pp.args, (
+            pp.path[:-1] + ".zip", "a", zipfile.ZIP_STORED, True,
+        ))
+        self.assertTrue(pp.args[0].endswith("/test.zip"))
 
     def test_zip_options(self):
         pp = self._create({
@@ -353,22 +364,13 @@ class ZipTest(BasePostprocessorTest):
             "extension": "cbz",
         })
         self.assertEqual(pp.delete, False)
-        self.assertEqual(pp.zfile.compression, zipfile.ZIP_DEFLATED)
-        self.assertTrue(pp.zfile.filename.endswith("/test.cbz"))
-
-    def test_zip_safe(self):
-        pp = self._create({"mode": "safe"})
-        self.assertEqual(pp.delete, True)
-        self.assertEqual(pp.path, self.pathfmt.realdirectory)
-        self.assertEqual(pp.run, pp._write_safe)
         self.assertEqual(pp.args, (
-            pp.path[:-1] + ".zip", "a", zipfile.ZIP_STORED, True,
+            pp.path[:-1] + ".cbz", "a", zipfile.ZIP_DEFLATED, True,
         ))
-        self.assertTrue(pp.args[0].endswith("/test.zip"))
+        self.assertTrue(pp.args[0].endswith("/test.cbz"))
 
     def test_zip_write(self):
         pp = self._create()
-        nti = pp.zfile.NameToInfo
 
         with tempfile.NamedTemporaryFile("w", dir=self.dir.name) as file:
             file.write("foobar\n")
@@ -382,6 +384,7 @@ class ZipTest(BasePostprocessorTest):
                 pp.prepare(self.pathfmt)
                 pp.run(self.pathfmt)
 
+                nti = pp.zfile.NameToInfo
                 self.assertEqual(len(nti), i+1)
                 self.assertIn(name, nti)