python - lambda排序列表奇怪的行为

Question

当我按列表(元组)中的第一个和第二个元素排序时，它有效，但按第三个元素排序不再有效 输入:

mylist=[('11', '82075.36', '8.15'), ('16', '82073.78', '12.92'),   ('13', '62077.99', '17.89'),]

请求:

print(sorted(mylist, key=lambda val: val[0]))
print(sorted(mylist, key=lambda val: val[1]))
print(sorted(mylist, key=lambda val: val[2]))

和输出:

[('11', '82075.36', '8.15'), ('13', '62077.99', '17.89'), ('16', '82073.78', '12.92')] # it is OK

<小时/>

[('13', '62077.99', '17.89'), ('16', '82073.78', '12.92'), ('11',  '82075.36', '8.15')] # it is OK`

<小时/>

[('16', '82073.78', '12.92'), ('13', '62077.99', '17.89'), ('11', '82075.36', '8.15')] # this seems to be not correct, can anybody explain why?

如果我从第三个 elm 中删除引号，它就可以工作，无论如何，对于 elm 1 来说，它可以在不删除引号的情况下工作

mylist=[('11', '82075.36', 8.15), ('16', '82073.78', 12.92), ('13', '62077.99', 17.89),]

和输出:

[('11', '82075.36', 8.15), ('16', '82073.78', 12.92), ('13', '62077.99', 17.89)]

Answer 1

您要求对字符串进行排序，因此您正在进行字符串排序。试试这个:

print(sorted(mylist, key=lambda val: int(val[0])))
print(sorted(mylist, key=lambda val: float(val[1])))
print(sorted(mylist, key=lambda val: float(val[2])))

即将排序键更改为数字。