python - 在逗号处拆分字符串，除非在括号环境中

Question

我想在逗号处拆分 Python 多行字符串，除非逗号位于括号表达式内。例如，字符串

{J. Doe, R. Starr}, {Lorem
{i}psum dolor }, Dol. sit., am. et.

应该拆分成

['{J. Doe, R. Starr}', '{Lorem\n{i}psum dolor }', 'Dol. sit.', 'am. et.']

这涉及括号匹配，因此正则表达式可能在这里无济于事。 PyParsing有commaSeparatedList除了 quoted (") 环境而不是 {}-delimited 环境，这几乎做了我需要的.

有什么提示吗？

Answer 1

编写您自己的自定义拆分函数:

 input_string = """{J. Doe, R. Starr}, {Lorem
 {i}psum dolor }, Dol. sit., am. et."""


 expected = ['{J. Doe, R. Starr}', '{Lorem\n{i}psum dolor }', 'Dol. sit.', 'am. et.']

 def split(s):
     parts = []
     bracket_level = 0
     current = []
     # trick to remove special-case of trailing chars
     for c in (s + ","):
         if c == "," and bracket_level == 0:
             parts.append("".join(current))
             current = []
         else:
             if c == "{":
                 bracket_level += 1
             elif c == "}":
                 bracket_level -= 1
             current.append(c)
     return parts

 assert split(input_string), expected