Question

我正在使用2个标准对列表进行排序：

index_sort = {'r1':1, 'r2':2, 'T1':3, 'r3':4, 'T2':5, 'T3':6}

Eall_pairsorted = sorted(Eall_pairsorted, key = lambda e: (index_sort[e[0]], index_sort2[e[1]]  ))

问题是我得到了：

['r1', 'r2', '++', '0.01 0.01', -56.19568267]
['r1', 'T1', '++', '0.01 0.017453292519943295', -56.19567285]
['r1', 'r3', '++', '0.01 0.01', -56.19568267]
['r1', 'T2', '++', '0.01 0.017453292519943295', -56.19567285]
['r1', 'T3', '++', '0.01 0.017453292519943295', -56.19568714]
['r2', 'T1', '++', '0.01 0.017453292519943295', -56.19567439]
['r2', 'r3', '++', '0.01 0.01', -56.19568267]
['r2', 'T2', '++', '0.01 0.017453292519943295', -56.1956784]
['r2', 'T3', '++', '0.01 0.017453292519943295', -56.19568357]
['T1', 'T2', '++', '0.017453292519943295 0.017453292519943295', -56.19566509]
['T1', 'T3', '++', '0.017453292519943295 0.017453292519943295', -56.19570279]
['r3', 'T1', '++', '0.01 0.017453292519943295', -56.1956784]
['r3', 'T2', '+-', '0.01 0.017453292519943295', -56.19567944]
['r3', 'T3', '++', '0.01 0.017453292519943295', -56.19568357]
['r3', 'T3', '--', '0.01 0.017453292519943295', -56.19568081]
['r3', 'T3', '+-', '0.01 0.017453292519943295', -56.19569063]
['r3', 'T3', '-+', '0.01 0.017453292519943295', -56.1956905]
['T2', 'T3', '++', '0.017453292519943295 0.017453292519943295', -56.19570279]
['T2', 'T3', '--', '0.017453292519943295 0.017453292519943295', -56.19570039]
['T2', 'T3', '+-', '0.017453292519943295 0.017453292519943295', -56.195661]
['T2', 'T3', '-+', '0.017453292519943295 0.017453292519943295', -56.19566132]

我希望将r3和T1切换成一行：

   ['r3', 'T1', '++', '0.01 0.017453292519943295', -56.1956784]

获得以下顺序：

['T1', 'r3', '++', '0.01 0.017453292519943295', -56.1956784]

我只想换掉T1＆＃39;和＆＃39; r3＆＃39;，而不是整个专栏。

任何提示如何操作？

Answer 1

你不能在排序的同时做到这一点，但事后你可以这样做：

Eall_pairsorted = sorted(Eall_pairsorted, key = lambda e: (e[0], e[1]))
Eall_pairsorted = [[e[1], e[0]] + e[2:] for e in Eall_pairsorted]

测试：

>>> Eall_pairsorted = [
...     ['r1', 'r2', '++', '0.01 0.01', -56.19568267],
...     ['r1', 'T1', '++', '0.01 0.017453292519943295', -56.19567285],
...     ['r1', 'r3', '++', '0.01 0.01', -56.19568267]
... ]
>>> Eall_pairsorted = [[e[1], e[0]] + e[2:] for e in Eall_pairsorted]
>>> Eall_pairsorted
[
    ['r2', 'r1', '++', '0.01 0.01', -56.19568267], 
    ['T1', 'r1', '++', '0.01 0.017453292519943295', -56.19567285], 
    ['r3', 'r1', '++', '0.01 0.01', -56.19568267]
]

Answer 2

在这种特定情况下，您是否只想重新排列列表中的前两个元素？或者你想在这里应用哪种一般规则？我认为你应该澄清你的问题。如果只有一个特定案例困扰您，则以下内容将起作用。

使用列表理解：

lst = [
    ['r1', 'r2', '++', '0.01 0.01', -56.19568267],
    ['r3', 'T1', '++', '0.01 0.017453292519943295', -56.19567285],
    ['r1', 'r3', '++', '0.01 0.01', -56.19568267]]

lst = [['T1', 'r3'] + x[2:] if x[0:2] == ['r3', 'T1'] else x for x in lst]

没有列表理解：

Eall_pairsorted = [
    ['r1', 'r2', '++', '0.01 0.01', -56.19568267],
    ['r3', 'T1', '++', '0.01 0.017453292519943295', -56.19567285],
    ['r1', 'r3', '++', '0.01 0.01', -56.19568267]]

for index, item in enumerate(Eall_pairsorted):
    if item[0:2] == ['r3', 'T1']:
        Eall_pairsorted[index][0:2] = ['T1', 'r3']

使用两个条件对Python列表进行排序

2 个答案: