【发布时间】：2015-10-12 21:22:46
【问题描述】：
这种插入排序错误地对除最后一个元素之外的所有元素进行了排序。这很奇怪，因为我有一个相同的函数，可以按不同的属性对所有元素进行排序。我尝试复制、粘贴和更改工作函数，但这似乎是徒劳的。
for i in range(1, len(metals)):
index = i
while index != 0 and metals[index].weightPerBar > metals[index - 1].weightPerBar:
metals[index], metals[index - 1] = metals[index - 1], metals[index]
index -= 1
谢谢
这是模块的其余部分：
class Metal(struct):
"""
Represents a single metal type, composed of:
:slot name (str): The name of the metal
:slot totalBars (int): The total number of bars
:slot weightPerBar (int): The weight of a single bar
:slot valuePerBar (int): The value of a single bar
:slot valuePerWeight (float): The value per weight of the metal
:slot barsTaken (int): The number of bars added to the satchel
"""
_slots = ((str, "name"), (int, "totalBars"), (int, "weightPerBar"), (int, "valuePerBar"), (float, "valuePerWeight"), (int, "barsTaken"))
pass
def createMetal(name, totalBars, weightPerBar, valuePerBar):
"""
Create and return a new Metal object.
:param name (str): The name of the metal
:param totalBars (int): The total number of bars
:param weightPerBar (int): The weight of a single bar
:param valuePerBar (int): The value of a single bar
:return: A newly initialized Metal object
:rtype: Metal
"""
new_metal = Metal(name, totalBars, weightPerBar, valuePerBar)
return new_metal
pass
def readMetals(fileName):
"""
Read the metals from a file whose format is:
metalName totalBars weightPerBar valuePerBar
:param fileName (str): The name of the file
:return: A list of Metal objects
:rtype: list
"""
metal_list = []
file = open(fileName)
for line in file:
line = line.split()
weight_per_bar = float(line[3])/float(line[2]) # creating derived value
new_metal = Metal(line[0], int(line[1]), int(line[2]), int(line[3]), weight_per_bar, 0)
metal_list += [new_metal]
return metal_list
pass
def sortMetalsByValuePerBar(metals):
"""
Sort the metals by value per bar using insertion sort. The list of
metals is modified in place to be ordered by value per bar.
:param metals (list of Metal): The list of metals
:return: None
:rtype: NoneType
"""
for i in range(1, len(metals)):
index = i
while index != 0 and metals[index].valuePerBar > metals[index - 1].valuePerBar:
metals[index], metals[index - 1] = metals[index - 1], metals[index]
index -= 1
pass
def sortMetalsByValuePerWeight(metals):
"""
Sort the metals by value per weight using insertion sort. The list of
metals is modified in place to be ordered by value per weight.
:param metals (list of Metal): The list of metals
:return: None
:rtype: NoneType
"""
for i in range(1, len(metals)):
index = i
while index != 0 and metals[index].weightPerBar > metals[index - 1].weightPerBar:
metals[index], metals[index - 1] = metals[index - 1], metals[index]
index -= 1
pass
【问题讨论】：
标签： python for-loop insertion-sort