如何在python中从多行字符串中删除特定的空行？

我正在使用模板创建多个.txt文件。某些文件将具有空值，因此我要删除生成的空行：

arg1 = '- this is the third line'
arg2 = '- this is the fourth line'
arg3 = ''
arg4 = '- this is the sixth line'

应用于模板时，结果为以下内容：

（内容为多行字符串）

从模板中：

This is the first line:

    $arg1
    $arg2
    $arg3
    $arg4

This is some other content whose possible empty lines need to be left alone.

因此，在我将此内容写入文件之前，我想删除那些难看的空行，因此看起来如下所示：

This is the first line:

        - this is the third line
        - this is the fourth line         
        - this is the sixth line

This is some other content whose possible empty lines need to be left alone.

for line, index_line in zip(content.splitlines(), range(1, 11)):
    if index_line in range(4, 11) and line == '    ':
        # command that will remove the empty line and save the new content

换句话说，我想删除特定行范围内的所有空行，如下所示：

This is the first line:

        - this is the third line
        - this is the fourth line         
        - this is the sixth line

This is some other content whose possible empty lines need to be left alone.

for line, index_line in zip(content.splitlines(), range(1, 11)):
    if index_line in range(4, 11) and line == '    ':
        # command that will remove the empty line and save the new content

另外，范围是不同的，因为这是我自己的代码片段，但给定示例的范围是：

范围（1,7）

#当我们通过第六行时停止

---

range（3,7）

#只检查给定范围内的行

您需要的函数是

list.pop（index）

---

如果范围可能不同，并且我们可以使用“^-\s”作为开始和停止删除空行的标志，那么您可以使用正则表达式

import re

s = '''This is the first line:

    - this is the third line
    - this is the fourth line

    - this is the sixth line


This is some other content whose possible empty lines need to be left alone.

Leave that last line alone.
'''

remove_empty = False
lines = []
for line in s.splitlines():
    l = line.strip()
    if l != '':
        dashed = (re.match('^-\s', l) is not None)
        if dashed and not remove_empty:
            # Now we need to start removing empty strings
            remove_empty = (re.match('^-\s', l) is not None)
        elif not dashed and remove_empty:
            # Now it is time to stop
            remove_empty = False
            lines.append('')

    if l != '' or not remove_empty:
        lines.append(line)

print '\n'.join(lines)
# This is the first line:
#
#     - this is the third line
#     - this is the fourth line
#     - this is the sixth line
#
# This is some other content whose possible empty lines need to be left alone.
#
# Leave that last line alone.

---

如果您确实知道范围，那么Aaron D可能会有更好的解决方案。

如果要删除多个连续行，则以前的版本将不起作用，因为

pop（）

会更改列表的结构，从而跳过对下一项的比较。保存索引并按相反顺序删除可以避免这种情况。