使用enumerate在python中打印前一行

Question

我有一个以下格式的文件

OperonID    GI      Synonym    Start    End  Strand Length  COG_number  Product
1132034 397671780   RVBD_0002   2052    3260    +   402 -   DNA polymerase III subunit beta
1132034 397671781   RVBD_0003   3280    4437    +   385 -   DNA replication and repair protein RecF
1132034 397671782   RVBD_0004   4434    4997    +   187 -   hypothetical protein
1132035 397671783   RVBD_0005   5123    7267    +   714 -   DNA gyrase subunit B
1132035 397671784   RVBD_0006   7302    9818    +   838 -   DNA gyrase subunit A
1132036 397671786   RVBD_0007Ac 11421   11528   -   35  -   hypothetical protein
1132036 397671787   RVBD_0007Bc 11555   11692   -   45  -   hypothetical protein
1132037 397671792   RVBD_0012   14089   14877   +   262 -   hypothetical protein

• 我需要每个操作ID的开始和结束坐标加上 在它自己的文件/字符串中串入。 e、 g.对于操作装置1132034，起始坐标为2052，且 端部坐标为4997，钢绞线为-

我知道到目前为止，我可能可以使用enumerate并拥有以下脚本

lines = open('operonmap.opr', 'r').read().splitlines()
operon_id = 1132034
start = ''
end = ''
strand = ''

for i,line in enumerate(lines):
      if str(operon_id) in line:
            start += line[28:33]
      else:
            end += line[i-1]
            operonline += start
            operonline += end
            operonline += '\n'

然后，如果这种脚本有效，我会编辑字符串“operonline”以只包含开始-结束和串信息。不幸的是，它不起作用，但我希望你能看到我的逻辑

我希望有人能帮忙

Answer 1

也许试试这种逻辑？它只是有一个临时变量，跟踪您看到的最后一个操作ID，并在更改后切换开始/结束：

In [21]: lines = open("test.csv").read().splitlines()

In [22]: lines
Out[22]:
['OperonID,GI,Synonym,Start,End,Strand,Length',
 '1132034,397671780,RVBD_0002,2052,3260,+,402',
 '1132034,397671781,RVBD_0003,3280,4437,+,385',
 '1132034,397671782,RVBD_0004,4434,4997,+,187',
 '1132035,397671783,RVBD_0005,5123,7267,+,714',
 '1132035,397671784,RVBD_0006,7302,9818,+,838',
 '1132036,397671786,RVBD_0007Ac,11421,11528,-,35',
 '1132036,397671787,RVBD_0007Bc,11555,11692,-,45',
 '1132037,397671792,RVBD_0012,14089,14877,+,262']

In [23]: cur_operonid = ''

In [24]: cur_end = None
In [27]: cur_start = None
    ...: for line in lines[1:]:
    ...:     cols = line.split(','). # or line.split('\t') for tab-delimit
    ...:     if cur_operonid != cols[0]:  # New OperonID reached
    ...:         if cur_start is not None:
    ...:             print(f"{cur_operonid} went from {cur_start} to {cur_end}")
    ...:         cur_operonid = cols[0]
    ...:         cur_start = cols[3]
    ...:     else:
    ...:         cur_end = cols[4]
    ...:
1132034 went from 2052 to 4997
1132035 went from 5123 to 9818
1132036 went from 11421 to 11692