python · doerwalter · Jun 6, 2017 · Apr 23, 2017 · Apr 24, 2017 · May 1, 2017
diff --git a/Doc/library/calendar.rst b/Doc/library/calendar.rst
@@ -147,7 +147,7 @@ it's the base calendar for all computations.
    This class can be used to generate HTML calendars.
 
 
-   :class:`HTMLCalendar` instances have the following methods:
+   :class:`!HTMLCalendar` instances have the following methods:
 
    .. method:: formatmonth(theyear, themonth, withyear=True)
 
@@ -171,6 +171,85 @@ it's the base calendar for all computations.
       output (defaulting to the system default encoding).
 
 
+   :class:`!HTMLCalendar` has the following attributes you can override to
+   customize the CSS classes used by the calendar:
+
+   .. attribute:: cssclasses
+
+      A list of CSS classes used for each weekday. The default class list is::
+
+         cssclasses = ["mon", "tue", "wed", "thu", "fri", "sat", "sun"]
+
+      more styles can be added for each day::
+
+         cssclasses = ["mon text-bold", "tue", "wed", "thu", "fri", "sat", "sun red"]
+
+      Note that the length of this list must be seven items.
+
+
+   .. attribute:: cssclass_noday
+
+      The CSS class for a weekday occurring in the previous or coming month.
+
+      .. versionadded:: 3.7
+
+
+   .. attribute:: cssclasses_weekday_head
+
+      A list of CSS classes used for weekday names in the header row.
+      The default is the same as :attr:`cssclasses`.
+
+      .. versionadded:: 3.7
+
+
+   .. attribute:: cssclass_month_head
+
+      The month's head CSS class (used by :meth:`formatmonthname`).
+      The default value is ``"month"``.
+
+      .. versionadded:: 3.7
+
+
+   .. attribute:: cssclass_month
+
+      The CSS class for the whole month's table (used by :meth:`formatmonth`).
+      The default value is ``"month"``.
+
+      .. versionadded:: 3.7
+
+
+   .. attribute:: cssclass_year
+
+      The CSS class for the whole year's table of tables (used by
+      :meth:`formatyear`). The default value is ``"year"``.
+
+      .. versionadded:: 3.7
+
+
+   .. attribute:: cssclass_year_head
+
+      The CSS class for the table head for the whole year (used by
+      :meth:`formatyear`). The default value is ``"year"``.
+
+      .. versionadded:: 3.7
+
+
+   Note that although the naming for the above described class attributes is
+   singular (e.g. ``cssclass_month`` ``cssclass_noday``), one can replace the
+   single CSS class with a space separated list of CSS classes, for example::
+
+         "text-bold text-red"
+
+   Here is an example how :class:`!HTMLCalendar` can be customized::
+
+       class CustomHTMLCal(calendar.HTMLCalendar):
+           cssclasses = [style + " text-nowrap" for style in
+                         calendar.HTMLCalendar.cssclasses]
+           cssclass_month_head = "text-center month-head"
+           cssclass_month = "text-center month"
+           cssclass_year = "text-italic lead"
+
+
 .. class:: LocaleTextCalendar(firstweekday=0, locale=None)
 
    This subclass of :class:`TextCalendar` can be passed a locale name in the

diff --git a/Doc/whatsnew/3.7.rst b/Doc/whatsnew/3.7.rst
@@ -103,13 +103,6 @@ New Modules
 Improved Modules
 ================
 
-cgi
----
-
-:func:`~cgi.parse_multipart` returns the same results as
-:class:`~FieldStorage` : for non-file fields, the value associated to a key
-is a list of strings, not bytes.
-(Contributed by Pierre Quentel in :issue:`29979`.)
 
 binascii
 --------
@@ -118,6 +111,22 @@ The :func:`~binascii.b2a_uu` function now accepts an optional *backtick*
 keyword argument.  When it's true, zeros are represented by ``'`'``
 instead of spaces.  (Contributed by Xiang Zhang in :issue:`30103`.)
 
+
+calendar
+--------
+
+The :class:`~calendar.HTMLCalendar` has added new class attribute which ease the
+customisation the CSS classes in the produced HTML calendar.
+(Contributed by Oz Tiram in :issue:`30095`.)
+
+cgi
+---
+
+:func:`~cgi.parse_multipart` returns the same results as
+:class:`~FieldStorage` : for non-file fields, the value associated to a key
+is a list of strings, not bytes.
+(Contributed by Pierre Quentel in :issue:`29979`.)
+
 contextlib
 ----------
 

diff --git a/Lib/calendar.py b/Lib/calendar.py
@@ -382,12 +382,31 @@ class HTMLCalendar(Calendar):
     # CSS classes for the day <td>s
     cssclasses = ["mon", "tue", "wed", "thu", "fri", "sat", "sun"]
 
+    # CSS classes for the day <th>s
+    cssclasses_weekday_head = cssclasses
+
+    # CSS class for the days before and after current month
+    cssclass_noday = "noday"
+
+    # CSS class for the month's head
+    cssclass_month_head = "month"
+
+    # CSS class for the month
+    cssclass_month = "month"
+
+    # CSS class for the year's table head
+    cssclass_year_head = "year"
+
+    # CSS class for the whole year table
+    cssclass_year = "year"
+
     def formatday(self, day, weekday):
         """
         Return a day as a table cell.
         """
         if day == 0:
-            return '<td class="noday">&nbsp;</td>' # day outside month
+            # day outside month
+            return '<td class="%s">&nbsp;</td>' % self.cssclass_noday
         else:
             return '<td class="%s">%d</td>' % (self.cssclasses[weekday], day)
 
@@ -402,7 +421,8 @@ def formatweekday(self, day):
         """
         Return a weekday name as a table header.
         """
-        return '<th class="%s">%s</th>' % (self.cssclasses[day], day_abbr[day])
+        return '<th class="%s">%s</th>' % (
+            self.cssclasses_weekday_head[day], day_abbr[day])
 
     def formatweekheader(self):
         """
@@ -419,15 +439,17 @@ def formatmonthname(self, theyear, themonth, withyear=True):
             s = '%s %s' % (month_name[themonth], theyear)
         else:
             s = '%s' % month_name[themonth]
-        return '<tr><th colspan="7" class="month">%s</th></tr>' % s
+        return '<tr><th colspan="7" class="%s">%s</th></tr>' % (
+            self.cssclass_month_head, s)
 
     def formatmonth(self, theyear, themonth, withyear=True):
         """
         Return a formatted month as a table.
         """
         v = []
         a = v.append
-        a('<table border="0" cellpadding="0" cellspacing="0" class="month">')
+        a('<table border="0" cellpadding="0" cellspacing="0" class="%s">' % (
+            self.cssclass_month))
         a('\n')
         a(self.formatmonthname(theyear, themonth, withyear=withyear))
         a('\n')
@@ -447,9 +469,11 @@ def formatyear(self, theyear, width=3):
         v = []
         a = v.append
         width = max(width, 1)
-        a('<table border="0" cellpadding="0" cellspacing="0" class="year">')
+        a('<table border="0" cellpadding="0" cellspacing="0" class="%s">' %
+          self.cssclass_year)
         a('\n')
-        a('<tr><th colspan="%d" class="year">%s</th></tr>' % (width, theyear))
+        a('<tr><th colspan="%d" class="%s">%s</th></tr>' % (
+            width, self.cssclass_year_head, theyear))
         for i in range(January, January+12, width):
             # months in this row
             months = range(i, min(i+width, 13))