相关疑难解决方法(0)

我正在使用Python,并希望在不删除或复制文件的情况下将字符串插入文本文件中.我怎样才能做到这一点？

我有一个文本文件,如下所示:

blah blah
foo1 bar1
foo1 bar2
foo1 bar3
foo2 bar4
foo2 bar5
blah blah

现在我想'foo bar'在'foo1 bar3'和之间插入'foo2 bar4'.

我就这样做了:

import shutil

txt = '1.txt'
tmptxt = '1.txt.tmp'

with open(tmptxt, 'w') as outfile:
    with open(txt, 'r') as infile:
        flag = 0
        for line in infile:
            if not line.startswith('foo1') and flag == 0:
                outfile.write(line)
                continue
            if line.startswith('foo1') and flag == 0:
                flag = 1
                outfile.write(line)
                continue
            if line.startswith('foo1') and flag == 1:
                outfile.write(line)
                continue
            if …