class OrderBy(object):
def __init__(self, sequence, *condition, **extra_condition):
"""
排序初始化条件
condition为优先排序条件,序列内元素必须为字典类型
extra_condition为额外的条件因素,当condition不存在时,额外条件才会生效
:param sequence:
:param condition:
:param extra_condition:
"""
self.array = sequence
self.condition = list(condition)
self.extra_condition = extra_condition
self.has_condition = bool(self.condition)
def partition(self, left, right, key=None, desc=False, func=None):
"""
将区间数据进行排序
分区比较,选择一个基准,根据排序规则,正序:比基准大的放右边,比基准小的放左边
:param left: 序列区间的开始位置
:param right: 序列区间的结束位置
:param key: 对于字典对象,如果指定key,则以key对象比较否则当None值处理
:param desc: 比较规则为正序或倒序
:param func: 对值进行处理特殊处理的函数
:return:
"""
pivot = self.array[left]
if isinstance(pivot, dict):
if key is not None:
pivot = pivot.get(key)
if callable(func):
pivot = func(pivot)
low = left
while low < right:
while low < right:
_left = self.array[low]
_right = self.array[right]
if isinstance(_left, dict):
_left = _left.get(key)
if isinstance(_right, dict):
_right = _right.get(key)
if callable(func):
_left = func(_left)
_right = func(_right)
if desc:
# 倒序,右边值与基准值都不为空,且右边值小于基准值,左移
if _right and pivot and _right < pivot:
right -= 1
# 倒序,右边值为空,左移
elif not _right:
right -= 1
# 倒序,左边值与基准值都不为空,且左边值大于等于基准值,右移
elif _left and pivot and _left >= pivot:
low += 1
# 倒序,基准值为空,左边值不为空,右移
elif _left and not pivot:
low += 1
else:
break
else:
# 正序,基准为空,右边值不为空,左移
if _right and not pivot:
right -= 1
# 正序,右边值与基准都不为空,且右边值大于基准值,左移
elif _right and pivot and _right > pivot:
right -= 1
# 正序,左边值与基准都不为空,且左边值小于等于基准值,右移
elif _left and pivot and _left <= pivot:
low += 1
# 正序,左边值为空,右移
elif not _left:
low += 1
else:
break
if low < right:
temp = self.array[low]
self.array[low] = self.array[right]
self.array[right] = temp
self.array[left], self.array[low] = self.array[low], self.array[left]
return low
def quick_sort(self, left=0, right=None, key=None, desc=False, func=None):
"""
快速排序算法
:param left: 区间起始位置
:param right: 区间结束位置
:param key: 字典元素使用指定键名值排序
:param desc: 是否倒序
:param func: 对于排序值,支持使用函数处理
:return:
"""
if right is None:
right = len(self.array) - 1
if left < right:
pivot_position = self.partition(left, right, key, desc, func)
self.quick_sort(left, pivot_position - 1, key, desc, func)
self.quick_sort(pivot_position + 1, right, key, desc, func)
def sort(self, **condition):
if self.has_condition:
if not self.condition:
return
_condition = self.condition.pop(0)
if isinstance(_condition, dict):
condition['key'] = _condition.get('key')
condition['desc'] = _condition.get('desc', False)
else:
condition.update(**self.extra_condition)
left = condition.get('left')
right = condition.get('right')
if not left:
left = 0
condition['left'] = left
if not right:
right = len(self.array) - 1
condition['right'] = right
self.quick_sort(**condition)
self.sub_sort(left, right, condition.get('key'))
def sub_sort(self, left, right, key=None, next_index=0):
"""
标记当前位置begin,及下一个位置end
当begin位置的元素与end位置元素不等时,当begin!=end - 1时,则进行区间排序
:param left: 区间起始位置
:param right: 区间结束位置
:param key: 当前排序键名
:param next_index: 下一个条件位置
:return:
"""
condition_size = len(self.condition)
if not condition_size > next_index:
return
begin = left
for end in range(left, right + 1):
_left = self.array[begin]
_right = self.array[end]
if isinstance(_left, dict):
_left = _left.get(key)
if isinstance(_right, dict):
_right = _right.get(key)
# 当上一个值与当前值不相等,则进入二次排序
# 当上一个值与当前值相等,且当前位置等于边界位置,且还有下一个排序条件,则进入二次排序
if _left != _right or (
end == right and condition_size >= next_index + 1):
condition = self.condition[next_index]
_key = condition.get('key')
desc = condition.get('desc')
func = condition.get('func')
if end == right:
_end = end
else:
_end = end - 1
self.quick_sort(begin, _end, _key, desc, func)
self.sub_sort(begin, end, _key, next_index + 1)
begin = end
if __name__ == '__main__':
a = [dict(age=18, money=200, name='z1'),
dict(age=16, money=200, name='z2'),
dict(age=16, money=200, name='z3'),
dict(age=16, money=100, name='z4'),
dict(age=16, money=200, name='z5')]
order_by = OrderBy(a, dict(key='age', desc=False),
dict(key='money', desc=True),
dict(key='name', desc=True))
print(a)
order_by.sort()
print(a)
快排实现仿order by多字段排序
原文作者:曾春云
原文地址: https://www.cnblogs.com/zengchunyun/p/10384372.html
本文转自网络文章,转载此文章仅为分享知识,如有侵权,请联系博主进行删除。
原文地址: https://www.cnblogs.com/zengchunyun/p/10384372.html
本文转自网络文章,转载此文章仅为分享知识,如有侵权,请联系博主进行删除。