astro-notion-blog想要对 list 分页的同时，还想知道当前页是否有 prev 和 next，类似如下操作：
paginator = Paginator(range(50), 12)
for page in paginator:
page.has_prev # 是否有 prev
page.has_next # 是否有 next
page.index # page 序号
for item in page:
item # 每个元素
不多说，上代码：
# coding : utf-8
# file : xpaginatior
# author : z4none@gmail.com
class Paginator:
def __init__(self, items, page_size):
self.items = items[:]
self.page_size = page_size
def __getitem__(self, index):
return Page(self.items, self.page_size, index)
return self.items[index * self.page_size: index * self.page_size + self.page_size]
def __iter__(self):
return Pages(self.items, self.page_size)
class Pages:
def __init__(self, items, page_size):
self.items = items
self.page_size = page_size
self.index = 0
def next(self):
if self.index * self.page_size > len(self.items): raise StopIteration
self.index = self.index + 1
return Page(self.items, self.page_size, self.index-1)
class Page:
def __init__(self, items, page_size, index):
total = len(items)
begin = index * page_size
end = index * page_size + page_size
self.items = items[begin: end]
self.has_prev = (begin > 0)
self.has_next = end < total
self.index = index
def __iter__(self):
return Items(self.items)
class Items:
def __init__(self, items):
self.items = items
self.index = 0
def next(self):
if self.index >= len(self.items): raise StopIteration
self.index = self.index + 1
return self.items[self.index-1]
def test():
paginator = Paginator(range(50), 12)
for pages in paginator:
print "[%02d]" % pages.index,
print (pages.has_prev and "<" or " "),
for item in pages:
print "%02d" % item,
print (pages.has_next and ">" or " "),
print
if __name__ == "__main__":
test()
以上代码输出结果：
[00] 00 01 02 03 04 05 06 07 08 09 10 11 >
[01] < 12 13 14 15 16 17 18 19 20 21 22 23 >
[02] < 24 25 26 27 28 29 30 31 32 33 34 35 >
[03] < 36 37 38 39 40 41 42 43 44 45 46 47 >
[04] < 48 49