Ran pyupgrade to Python 3.7+ (then fade to black).

cssutils/_fetch.py

@@ -29,7 +29,7 @@ def _defaultFetcher(url):
         res = urllib.request.urlopen(request)
     except urllib.error.HTTPError as e:
         # http error, e.g. 404, e can be raised
-        log.warn('HTTPError opening url=%s: %s %s' % (url, e.code, e.msg), error=e)
+        log.warn(f'HTTPError opening url={url}: {e.code} {e.msg}', error=e)
     except urllib.error.URLError as e:
         # URLError like mailto: or other IO errors, e can be raised
         log.warn('URLError, %s' % e.reason, error=e)

cssutils/_fetchgae.py

@@ -45,7 +45,7 @@ def _defaultFetcher(url):
     try:
         r = urlfetch.fetch(url, method=urlfetch.GET)
     except urlfetch.Error as e:
-        log.warn('Error opening url=%r: %s' % (url, e), error=IOError)
+        log.warn(f'Error opening url={url!r}: {e}', error=IOError)
     else:
         if r.status_code == 200:
             # find mimetype and encoding
@@ -65,6 +65,6 @@ def _defaultFetcher(url):
         else:
             # TODO: 301 etc
             log.warn(
-                'Error opening url=%r: HTTP status %s' % (url, r.status_code),
+                f'Error opening url={url!r}: HTTP status {r.status_code}',
                 error=IOError,
             )

cssutils/css/csscharsetrule.py

@@ -46,9 +46,7 @@ def __init__(
         :param readonly:
             defaults to False, not used yet
         """
-        super(CSSCharsetRule, self).__init__(
-            parentRule=parentRule, parentStyleSheet=parentStyleSheet
-        )
+        super().__init__(parentRule=parentRule, parentStyleSheet=parentStyleSheet)
         self._atkeyword = '@charset'
 
         if encoding:
@@ -59,10 +57,12 @@ def __init__(
         self._readonly = readonly
 
     def __repr__(self):
-        return "cssutils.css.%s(encoding=%r)" % (self.__class__.__name__, self.encoding)
+        return "cssutils.css.{}(encoding={!r})".format(
+            self.__class__.__name__, self.encoding
+        )
 
     def __str__(self):
-        return "<cssutils.css.%s object encoding=%r at 0x%x>" % (
+        return "<cssutils.css.{} object encoding={!r} at 0x{:x}>".format(
             self.__class__.__name__,
             self.encoding,
             id(self),
@@ -89,7 +89,7 @@ def _setCssText(self, cssText):
             - :exc:`~xml.dom.NoModificationAllowedErr`:
               Raised if the rule is readonly.
         """
-        super(CSSCharsetRule, self)._setCssText(cssText)
+        super()._setCssText(cssText)
 
         wellformed = True
         tokenizer = self._tokenize2(cssText)

cssutils/css/csscomment.py

@@ -22,9 +22,7 @@ class CSSComment(cssrule.CSSRule):
     def __init__(
         self, cssText=None, parentRule=None, parentStyleSheet=None, readonly=False
     ):
-        super(CSSComment, self).__init__(
-            parentRule=parentRule, parentStyleSheet=parentStyleSheet
-        )
+        super().__init__(parentRule=parentRule, parentStyleSheet=parentStyleSheet)
 
         self._cssText = None
         if cssText:
@@ -33,10 +31,12 @@ def __init__(
         self._readonly = readonly
 
     def __repr__(self):
-        return "cssutils.css.%s(cssText=%r)" % (self.__class__.__name__, self.cssText)
+        return "cssutils.css.{}(cssText={!r})".format(
+            self.__class__.__name__, self.cssText
+        )
 
     def __str__(self):
-        return "<cssutils.css.%s object cssText=%r at 0x%x>" % (
+        return "<cssutils.css.{} object cssText={!r} at 0x{:x}>".format(
             self.__class__.__name__,
             self.cssText,
             id(self),
@@ -62,7 +62,7 @@ def _setCssText(self, cssText):
             - :exc:`~xml.dom.NoModificationAllowedErr`:
               Raised if the rule is readonly.
         """
-        super(CSSComment, self)._setCssText(cssText)
+        super()._setCssText(cssText)
         tokenizer = self._tokenize2(cssText)
 
         commenttoken = self._nexttoken(tokenizer)

cssutils/css/cssfontfacerule.py

@@ -40,9 +40,7 @@ def __init__(
             CSSStyleDeclaration used to hold any font descriptions
             for this CSSFontFaceRule
         """
-        super(CSSFontFaceRule, self).__init__(
-            parentRule=parentRule, parentStyleSheet=parentStyleSheet
-        )
+        super().__init__(parentRule=parentRule, parentStyleSheet=parentStyleSheet)
         self._atkeyword = '@font-face'
 
         if style:
@@ -53,13 +51,13 @@ def __init__(
         self._readonly = readonly
 
     def __repr__(self):
-        return "cssutils.css.%s(style=%r)" % (
+        return "cssutils.css.{}(style={!r})".format(
             self.__class__.__name__,
             self.style.cssText,
         )
 
     def __str__(self):
-        return "<cssutils.css.%s object style=%r valid=%r at 0x%x>" % (
+        return "<cssutils.css.{} object style={!r} valid={!r} at 0x{:x}>".format(
             self.__class__.__name__,
             self.style.cssText,
             self.valid,
@@ -85,7 +83,7 @@ def _setCssText(self, cssText):
             - :exc:`~xml.dom.NoModificationAllowedErr`:
               Raised if the rule is readonly.
         """
-        super(CSSFontFaceRule, self)._setCssText(cssText)
+        super()._setCssText(cssText)
 
         tokenizer = self._tokenize2(cssText)
         attoken = self._nexttoken(tokenizer, None)

cssutils/css/cssimportrule.py

@@ -42,9 +42,7 @@ def __init__(
         :param name:
             Additional name of imported style sheet
         """
-        super(CSSImportRule, self).__init__(
-            parentRule=parentRule, parentStyleSheet=parentStyleSheet
-        )
+        super().__init__(parentRule=parentRule, parentStyleSheet=parentStyleSheet)
         self._atkeyword = '@import'
         self._styleSheet = None
 
@@ -76,7 +74,7 @@ def __repr__(self):
             mediaText = self.media.mediaText
         else:
             mediaText = None
-        return "cssutils.css.%s(href=%r, mediaText=%r, name=%r)" % (
+        return "cssutils.css.{}(href={!r}, mediaText={!r}, name={!r})".format(
             self.__class__.__name__,
             self.href,
             mediaText,
@@ -88,7 +86,7 @@ def __str__(self):
             mediaText = self.media.mediaText
         else:
             mediaText = None
-        return "<cssutils.css.%s object href=%r mediaText=%r name=%r at 0x%x>" % (
+        return "<cssutils.css.{} object href={!r} mediaText={!r} name={!r} at 0x{:x}>".format(
             self.__class__.__name__,
             self.href,
             mediaText,
@@ -120,7 +118,7 @@ def _setCssText(self, cssText):  # noqa: C901
               Raised if the specified CSS string value has a syntax error and
               is unparsable.
         """
-        super(CSSImportRule, self)._setCssText(cssText)
+        super()._setCssText(cssText)
         tokenizer = self._tokenize2(cssText)
         attoken = self._nexttoken(tokenizer, None)
         if self._type(attoken) != self._prods.IMPORT_SYM:
@@ -314,7 +312,7 @@ def _setHref(self, href):
 
                 if cssText is None:
                     # catched in next except below!
-                    raise IOError('Cannot read Stylesheet.')
+                    raise OSError('Cannot read Stylesheet.')
 
                 # contentEncoding with parentStyleSheet.overrideEncoding,
                 # HTTP or parent
@@ -332,7 +330,7 @@ def _setHref(self, href):
                     cssText, encodingOverride=encodingOverride, encoding=encoding
                 )
 
-            except (OSError, IOError, ValueError) as e:
+            except (OSError, ValueError) as e:
                 self._log.warn(
                     'CSSImportRule: While processing imported '
                     'style sheet href=%s: %r' % (self.href, e),

cssutils/css/cssmediarule.py

@@ -33,9 +33,7 @@ def __init__(
         readonly=False,
     ):
         """constructor"""
-        super(CSSMediaRule, self).__init__(
-            parentRule=parentRule, parentStyleSheet=parentStyleSheet
-        )
+        super().__init__(parentRule=parentRule, parentStyleSheet=parentStyleSheet)
         self._atkeyword = '@media'
 
         # 1. media
@@ -48,13 +46,13 @@ def __init__(
         self._readonly = readonly
 
     def __repr__(self):
-        return "cssutils.css.%s(mediaText=%r)" % (
+        return "cssutils.css.{}(mediaText={!r})".format(
             self.__class__.__name__,
             self.media.mediaText,
         )
 
     def __str__(self):
-        return "<cssutils.css.%s object mediaText=%r at 0x%x>" % (
+        return "<cssutils.css.{} object mediaText={!r} at 0x{:x}>".format(
             self.__class__.__name__,
             self.media.mediaText,
             id(self),
@@ -85,7 +83,7 @@ def _setCssText(self, cssText):  # noqa: C901
               Raised if the rule is readonly.
         """
         # media "name"? { cssRules }
-        super(CSSMediaRule, self)._setCssText(cssText)
+        super()._setCssText(cssText)
 
         # might be (cssText, namespaces)
         cssText, namespaces = self._splitNamespacesOff(cssText)

cssutils/css/cssnamespacerule.py

@@ -67,9 +67,7 @@ def __init__(
               : IDENT
               ;
         """
-        super(CSSNamespaceRule, self).__init__(
-            parentRule=parentRule, parentStyleSheet=parentStyleSheet
-        )
+        super().__init__(parentRule=parentRule, parentStyleSheet=parentStyleSheet)
         self._atkeyword = '@namespace'
         self._prefix = ''
         self._namespaceURI = None
@@ -91,18 +89,20 @@ def __init__(
         self._readonly = readonly
 
     def __repr__(self):
-        return "cssutils.css.%s(namespaceURI=%r, prefix=%r)" % (
+        return "cssutils.css.{}(namespaceURI={!r}, prefix={!r})".format(
             self.__class__.__name__,
             self.namespaceURI,
             self.prefix,
         )
 
     def __str__(self):
-        return "<cssutils.css.%s object namespaceURI=%r prefix=%r at 0x%x>" % (
-            self.__class__.__name__,
-            self.namespaceURI,
-            self.prefix,
-            id(self),
+        return (
+            "<cssutils.css.{} object namespaceURI={!r} prefix={!r} at 0x{:x}>".format(
+                self.__class__.__name__,
+                self.namespaceURI,
+                self.prefix,
+                id(self),
+            )
         )
 
     def _getCssText(self):
@@ -125,7 +125,7 @@ def _setCssText(self, cssText):  # noqa: C901
               Raised if the specified CSS string value has a syntax error and
               is unparsable.
         """
-        super(CSSNamespaceRule, self)._setCssText(cssText)
+        super()._setCssText(cssText)
         tokenizer = self._tokenize2(cssText)
         attoken = self._nexttoken(tokenizer, None)
         if self._type(attoken) != self._prods.NAMESPACE_SYM:

cssutils/css/csspagerule.py

@@ -69,9 +69,7 @@ def __init__(
         :param style:
             CSSStyleDeclaration for this CSSStyleRule
         """
-        super(CSSPageRule, self).__init__(
-            parentRule=parentRule, parentStyleSheet=parentStyleSheet
-        )
+        super().__init__(parentRule=parentRule, parentStyleSheet=parentStyleSheet)
         self._atkeyword = '@page'
         self._specificity = (0, 0, 0)
 
@@ -94,7 +92,7 @@ def __init__(
         self._readonly = readonly
 
     def __repr__(self):
-        return "cssutils.css.%s(selectorText=%r, style=%r)" % (
+        return "cssutils.css.{}(selectorText={!r}, style={!r})".format(
             self.__class__.__name__,
             self.selectorText,
             self.style.cssText,
@@ -299,7 +297,7 @@ def _setCssText(self, cssText):
             - :exc:`~xml.dom.NoModificationAllowedErr`:
               Raised if the rule is readonly.
         """
-        super(CSSPageRule, self)._setCssText(cssText)
+        super()._setCssText(cssText)
 
         tokenizer = self._tokenize2(cssText)
         if self._type(self._nexttoken(tokenizer)) != self._prods.PAGE_SYM:

cssutils/css/cssrule.py

@@ -61,7 +61,7 @@ class CSSRule(cssutils.util.Base2):
 
     def __init__(self, parentRule=None, parentStyleSheet=None, readonly=False):
         """Set common attributes for all rules."""
-        super(CSSRule, self).__init__()
+        super().__init__()
         self._parent = parentRule
         self._parentRule = parentRule
         self._parentStyleSheet = parentStyleSheet
@@ -78,7 +78,9 @@ def _setAtkeyword(self, keyword):
             self._keyword = keyword
         else:
             self._log.error(
-                '%s: Invalid atkeyword for this rule: %r' % (self.atkeyword, keyword),
+                '{}: Invalid atkeyword for this rule: {!r}'.format(
+                    self.atkeyword, keyword
+                ),
                 error=xml.dom.InvalidModificationErr,
             )
 
@@ -160,16 +162,13 @@ class CSSRuleRules(CSSRule):
 
     def __init__(self, parentRule=None, parentStyleSheet=None):
 
-        super(CSSRuleRules, self).__init__(
-            parentRule=parentRule, parentStyleSheet=parentStyleSheet
-        )
+        super().__init__(parentRule=parentRule, parentStyleSheet=parentStyleSheet)
 
         self.cssRules = cssutils.css.CSSRuleList()
 
     def __iter__(self):
         """Generator iterating over these rule's cssRules."""
-        for rule in self._cssRules:
-            yield rule
+        yield from self._cssRules
 
     def _setCssRules(self, cssRules):
         "Set new cssRules and update contained rules refs."
@@ -257,7 +256,7 @@ def _prepareInsertRule(self, rule, index=None):
                 and not isinstance(tempsheet.cssRules[0], cssutils.css.CSSRule)
             ):
                 self._log.error(
-                    '%s: Invalid Rule: %s' % (self.__class__.__name__, rule)
+                    '{}: Invalid Rule: {}'.format(self.__class__.__name__, rule)
                 )
                 return False, False
             rule = tempsheet.cssRules[0]
@@ -269,7 +268,9 @@ def _prepareInsertRule(self, rule, index=None):
             return True, True
 
         elif not isinstance(rule, cssutils.css.CSSRule):
-            self._log.error('%s: Not a CSSRule: %s' % (rule, self.__class__.__name__))
+            self._log.error(
+                '{}: Not a CSSRule: {}'.format(rule, self.__class__.__name__)
+            )
             return False, False
 
         return rule, index