Python:如何分割线合并一些线

Question

我想逐行处理一个字符串，但我想启用多行支持。这是示例文本:

First line
Second line
{{{
these three lines
I want to process
together
}}}
Last Line

我希望多行从 {{{ 开始并在 }} 结束我以前是按以下方式逐行处理的:

lines = [l for l in text.splitlines()]
print lines

现在这段代码输出:

['First line', 'Second line', '{{{', 'these three lines', 'I want to process', 'together', '}}}', 'Last Line']

我想以某种方式使行包含以下内容:

['First line', 'Second line', 'these three lines I want to process together', 'Last Line']

或者，更高级的例子

First Line
Second line
Third{{{line
fourth line
fifth}}}line
sixth line

在这种情况下，我希望行包含

['First Line', 'Second line', 'Third', 'line fourth line fifth', 'line', 'sixth line']

Answer 1

这是一个生成器，它将输入文件对象作为参数，一次生成一行。它应该在同一行接受尽可能多的 {{{ 和 }}} 但不测试不平衡的结构:

def merge_lines(fd):
    concat = False
    for line in fd:
        while True:
            #print (line)
            if len(line.strip()) == 0: break
            if not concat:
                if ('{{{' in line):
                    deb, line = line.split('{{{', 1)
                    yield deb
                    concat = True
                    old = None
                else:
                    yield line.strip('\r\n')
                    line = ""
            if concat:
                if ('}}}' in line):
                    deb, line = line.split('}}}', 1)
                    concat = False
                    if old:
                        yield old.strip() + ' ' + deb
                    else: yield deb
                else:
                    if old:
                        old += ' ' + line.strip('\r\n')
                    else:
                        old = line.strip('\r\n')
                    line = ""

Python 3 中的示例:

>>> t = """First line
a{{{b}}}c{{{d
e
f}}}g{{{h
i}}}
j
k
"""
>>> for line in merge_lines(io.StringIO(t)): print(line)

First line
a
b
c
d e f
g
h i
j
k