Linting fixes for preview image code

bookwyrm/management/commands/generate_preview_images.py

@@ -1,12 +1,12 @@
 """ Generate preview images """
-import sys
-
 from django.core.management.base import BaseCommand
 
-from bookwyrm import activitystreams, models, settings, preview_images
+from bookwyrm import models, preview_images
 
 
+# pylint: disable=line-too-long
 class Command(BaseCommand):
+    """Creates previews for existing objects"""
     help = "Generate preview images"
 
     def add_arguments(self, parser):

bookwyrm/preview_images.py

@@ -1,13 +1,14 @@
-import colorsys
+""" Generate social media preview images for twitter/mastodon/etc """
 import math
 import os
 import textwrap
-
-from colorthief import ColorThief
 from io import BytesIO
-from PIL import Image, ImageDraw, ImageFont, ImageOps, ImageColor
 from uuid import uuid4
 
+import colorsys
+from colorthief import ColorThief
+from PIL import Image, ImageDraw, ImageFont, ImageOps, ImageColor
+
 from django.core.files.base import ContentFile
 from django.core.files.uploadedfile import InMemoryUploadedFile
 from django.db.models import Avg
@@ -31,6 +32,7 @@ font_dir = os.path.join(settings.STATIC_ROOT, "fonts/public_sans")
 
 
 def get_font(font_name, size=28):
+    """Loads custom font"""
     if font_name == "light":
         font_path = os.path.join(font_dir, "PublicSans-Light.ttf")
     if font_name == "regular":
@@ -47,6 +49,7 @@ def get_font(font_name, size=28):
 
 
 def generate_texts_layer(texts, content_width):
+    """Adds text for images"""
     font_text_zero = get_font("bold", size=20)
     font_text_one = get_font("bold", size=48)
     font_text_two = get_font("bold", size=40)
@@ -66,7 +69,7 @@ def generate_texts_layer(texts, content_width):
 
         try:
             text_y = text_y + font_text_zero.getsize_multiline(text_zero)[1] + 16
-        except:
+        except (AttributeError, IndexError):
             text_y = text_y + 26
 
     if "text_one" in texts and texts["text_one"]:
@@ -78,7 +81,7 @@ def generate_texts_layer(texts, content_width):
 
         try:
             text_y = text_y + font_text_one.getsize_multiline(text_one)[1] + 16
-        except:
+        except (AttributeError, IndexError):
             text_y = text_y + 26
 
     if "text_two" in texts and texts["text_two"]:
@@ -90,7 +93,7 @@ def generate_texts_layer(texts, content_width):
 
         try:
             text_y = text_y + font_text_one.getsize_multiline(text_two)[1] + 16
-        except:
+        except (AttributeError, IndexError):
             text_y = text_y + 26
 
     if "text_three" in texts and texts["text_three"]:
@@ -105,6 +108,7 @@ def generate_texts_layer(texts, content_width):
 
 
 def generate_instance_layer(content_width):
+    """Places components for instance preview"""
     font_instance = get_font("light", size=28)
 
     site = models.SiteSettings.objects.get()
@@ -145,7 +149,7 @@ def generate_instance_layer(content_width):
 
 
 def generate_rating_layer(rating, content_width):
-    try:
+    """Places components for rating preview"""
     icon_star_full = Image.open(
         os.path.join(settings.STATIC_ROOT, "images/icons/star-full.png")
     )
@@ -171,7 +175,7 @@ def generate_rating_layer(rating, content_width):
 
     position_x = 0
 
-        for r in range(math.floor(rating)):
+    for _ in range(math.floor(rating)):
         rating_layer_mask.alpha_composite(icon_star_full, (position_x, 0))
         position_x = position_x + icon_size + icon_margin
 
@@ -179,7 +183,7 @@ def generate_rating_layer(rating, content_width):
         rating_layer_mask.alpha_composite(icon_star_half, (position_x, 0))
         position_x = position_x + icon_size + icon_margin
 
-        for r in range(5 - math.ceil(rating)):
+    for _ in range(5 - math.ceil(rating)):
         rating_layer_mask.alpha_composite(icon_star_empty, (position_x, 0))
         position_x = position_x + icon_size + icon_margin
 
@@ -191,11 +195,10 @@ def generate_rating_layer(rating, content_width):
     )
 
     return rating_layer_composite
-    except:
-        return None
 
 
 def generate_default_inner_img():
+    """Adds cover image"""
     font_cover = get_font("light", size=28)
 
     default_cover = Image.new(
@@ -214,16 +217,19 @@ def generate_default_inner_img():
     return default_cover
 
 
+# pylint: disable=too-many-locals
 def generate_preview_image(
-    texts={}, picture=None, rating=None, show_instance_layer=True
+    texts=None, picture=None, rating=None, show_instance_layer=True
 ):
+    """Puts everything together"""
+    texts = texts or {}
     # Cover
     try:
         inner_img_layer = Image.open(picture)
         inner_img_layer.thumbnail((inner_img_width, inner_img_height), Image.ANTIALIAS)
         color_thief = ColorThief(picture)
         dominant_color = color_thief.get_color(quality=1)
-    except:
+    except:  # pylint: disable=bare-except
         inner_img_layer = generate_default_inner_img()
         dominant_color = ImageColor.getrgb(DEFAULT_COVER_COLOR)
 
@@ -246,7 +252,7 @@ def generate_preview_image(
             image_bg_color_hls[2],
         )
         image_bg_color = tuple(
-            [math.ceil(x * 255) for x in colorsys.hls_to_rgb(*image_bg_color_hls)]
+            math.ceil(x * 255) for x in colorsys.hls_to_rgb(*image_bg_color_hls)
         )
     else:
         image_bg_color = BG_COLOR
@@ -292,8 +298,7 @@ def generate_preview_image(
         # Remove Instance Layer from centering calculations
         contents_y = contents_y - math.floor((instance_layer.height + gutter) / 2)
 
-    if contents_y < margin:
-        contents_y = margin
+    contents_y = max(contents_y, margin)
 
     # Composite layers
     img.paste(
@@ -305,7 +310,9 @@ def generate_preview_image(
 
 
 def save_and_cleanup(image, instance=None):
-    if isinstance(instance, (models.Book, models.User, models.SiteSettings)):
+    """Save and close the file"""
+    if not isinstance(instance, (models.Book, models.User, models.SiteSettings)):
+        return False
     file_name = "%s-%s.jpg" % (str(instance.id), str(uuid4()))
     image_buffer = BytesIO()
 
@@ -329,7 +336,7 @@ def save_and_cleanup(image, instance=None):
 
         save_without_broadcast = isinstance(instance, (models.Book, models.User))
         if save_without_broadcast:
-                result = instance.save(broadcast=False)
+            instance.save(broadcast=False)
         else:
             instance.save()
 
@@ -340,14 +347,15 @@ def save_and_cleanup(image, instance=None):
     finally:
         image_buffer.close()
     return True
-    else:
-        return False
 
 
+# pylint: disable=invalid-name
 @app.task
 def generate_site_preview_image_task():
     """generate preview_image for the website"""
-    if settings.ENABLE_PREVIEW_IMAGES == True:
+    if not settings.ENABLE_PREVIEW_IMAGES:
+        return
+
     site = models.SiteSettings.objects.get()
 
     if site.logo:
@@ -368,10 +376,13 @@ def generate_site_preview_image_task():
     save_and_cleanup(image, instance=site)
 
 
+# pylint: disable=invalid-name
 @app.task
 def generate_edition_preview_image_task(book_id):
     """generate preview_image for a book"""
-    if settings.ENABLE_PREVIEW_IMAGES == True:
+    if not settings.ENABLE_PREVIEW_IMAGES:
+        return
+
     book = models.Book.objects.select_subclasses().get(id=book_id)
 
     rating = models.Review.objects.filter(
@@ -394,7 +405,9 @@ def generate_edition_preview_image_task(book_id):
 @app.task
 def generate_user_preview_image_task(user_id):
     """generate preview_image for a book"""
-    if settings.ENABLE_PREVIEW_IMAGES == True:
+    if not settings.ENABLE_PREVIEW_IMAGES:
+        return
+
     user = models.User.objects.get(id=user_id)
 
     texts = {

bookwyrm/tests/test_preview_images.py

@@ -18,9 +18,9 @@ from bookwyrm.preview_images import (
     save_and_cleanup,
 )
 
-import logging
-
 
+# pylint: disable=unused-argument
+# pylint: disable=missing-function-docstring
 class PreviewImages(TestCase):
     """every response to a get request, html or json"""