Python 按特定列对字符串排序

我需要对文本文件进行排序。该文件包含行，行之间用新行分隔

'\n'

。 输入示例：

ATOM   1591  O5'   G A 958       5.497  -3.281   3.598  1.00 99.99           O  
ATOM   1592  C5'   G A 958       4.345  -3.184   2.781  1.00 99.99           C 
ATOM      1  P     C A 924     -12.106   6.485 -14.650  1.00 99.99           P  
ATOM      2  OP1   C A 924     -12.981   6.565 -15.850  1.00 99.99           O  
ATOM      3  OP2   C A 924     -10.829   7.256 -14.620  1.00 99.99           O 
ATOM    429 2H4    C A 947       1.295  -1.142  -0.764  1.00 99.99           H  
ATOM    430  P     G A 948      -2.886  -4.112   7.863  1.00 99.99           P   

我想按第6列对它们进行排序（

958

，

924

等）

我试过这样做：

splitted = pdb_data.splitlines()
sorted(splitted, key = lambda residue: int(residue.split()[5]))
pdb_data = '\n'.join(splitted)
pdb_data +='\nTER\n'

---

但它没有分类-/

您使用了错误的方法进行排序；要就地排序，请使用：

返回一个新列表，保留原始列表未排序，但您的代码忽略返回值

您还可以将

sorted（）

的返回值分配回

splitted

，但这在这里效率很低

您的排序本身工作正常：

>>> splitted = '''\
... ATOM   1591  O5'   G A 958       5.497  -3.281   3.598  1.00 99.99           O  
... ATOM   1592  C5'   G A 958       4.345  -3.184   2.781  1.00 99.99           C 
... ATOM      1  P     C A 924     -12.106   6.485 -14.650  1.00 99.99           P  
... ATOM      2  OP1   C A 924     -12.981   6.565 -15.850  1.00 99.99           O  
... ATOM      3  OP2   C A 924     -10.829   7.256 -14.620  1.00 99.99           O 
... ATOM    429 2H4    C A 947       1.295  -1.142  -0.764  1.00 99.99           H  
... ATOM    430  P     G A 948      -2.886  -4.112   7.863  1.00 99.99           P   
... '''.splitlines()
>>> splitted.sort(key = lambda residue: int(residue.split()[5]))
>>> pdb_data = '\n'.join(splitted)
>>> print pdb_data
ATOM      1  P     C A 924     -12.106   6.485 -14.650  1.00 99.99           P  
ATOM      2  OP1   C A 924     -12.981   6.565 -15.850  1.00 99.99           O  
ATOM      3  OP2   C A 924     -10.829   7.256 -14.620  1.00 99.99           O 
ATOM    429 2H4    C A 947       1.295  -1.142  -0.764  1.00 99.99           H  
ATOM    430  P     G A 948      -2.886  -4.112   7.863  1.00 99.99           P   
ATOM   1591  O5'   G A 958       5.497  -3.281   3.598  1.00 99.99           O  
ATOM   1592  C5'   G A 958       4.345  -3.184   2.781  1.00 99.99           C 

splitted.sort(key = lambda residue: int(residue.split()[5]))

>>> splitted = '''\
... ATOM   1591  O5'   G A 958       5.497  -3.281   3.598  1.00 99.99           O  
... ATOM   1592  C5'   G A 958       4.345  -3.184   2.781  1.00 99.99           C 
... ATOM      1  P     C A 924     -12.106   6.485 -14.650  1.00 99.99           P  
... ATOM      2  OP1   C A 924     -12.981   6.565 -15.850  1.00 99.99           O  
... ATOM      3  OP2   C A 924     -10.829   7.256 -14.620  1.00 99.99           O 
... ATOM    429 2H4    C A 947       1.295  -1.142  -0.764  1.00 99.99           H  
... ATOM    430  P     G A 948      -2.886  -4.112   7.863  1.00 99.99           P   
... '''.splitlines()
>>> splitted.sort(key = lambda residue: int(residue.split()[5]))
>>> pdb_data = '\n'.join(splitted)
>>> print pdb_data
ATOM      1  P     C A 924     -12.106   6.485 -14.650  1.00 99.99           P  
ATOM      2  OP1   C A 924     -12.981   6.565 -15.850  1.00 99.99           O  
ATOM      3  OP2   C A 924     -10.829   7.256 -14.620  1.00 99.99           O 
ATOM    429 2H4    C A 947       1.295  -1.142  -0.764  1.00 99.99           H  
ATOM    430  P     G A 948      -2.886  -4.112   7.863  1.00 99.99           P   
ATOM   1591  O5'   G A 958       5.497  -3.281   3.598  1.00 99.99           O  
ATOM   1592  C5'   G A 958       4.345  -3.184   2.781  1.00 99.99           C