如何使用正则表达式在 python 字符串中找到 str.format 的所有占位符? [英] How can I find all placeholders for str.format in a python string using a regex?

问题描述

我正在创建一个使用用户指定格式重命名文件的类.此格式将是一个简单的字符串，其 str.format 方法将被调用以填充空格.

I'm creating a class that renames a file using a user-specified format. This format will be a simple string whose str.format method will be called to fill in the blanks.

事实证明，我的过程需要提取包含在大括号中的变量名称.例如，一个字符串可能包含 {user}，它应该产生 user.当然，单个字符串中会有几组大括号，我需要按照它们出现的顺序获取每组的内容并将它们输出到列表中.

It turns out that my procedure will require extracting variable names contained in braces. For example, a string may contain {user}, which should yield user. Of course, there will be several sets of braces in a single string, and I'll need to get the contents of each, in the order in which they appear and output them to a list.

因此，"{foo}{bar}" 应该产生 ['foo', 'bar'].

我怀疑最简单的方法是使用 re.split，但我对正则表达式一无所知.有人可以帮我吗?

I suspect that the easiest way to do this is to use re.split, but I know nothing about regular expressions. Can someone help me out?

提前致谢！

推荐答案

Using re.findall():

In [5]: import re

In [8]: strs = "{foo} spam eggs {bar}"

In [9]: re.findall(r"{(\w+)}", strs)
Out[9]: ['foo', 'bar']

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