Bracex

Bracex is a brace expanding library (à la Bash) for Python. Brace expanding is used to generate arbitrary strings.

$ echo {{a,b},c}d
ad bd cd

Bracex adds this ability to Python:

>>> bracex.expand(r'file-{{a,b},c}d.txt')
['file-ad.txt', 'file-bd.txt', 'file-cd.txt']

and as a command:

$ python3 -m bracex -0 "base/{a,b}/{1..2}" | xargs -0 mkdir -p
$ tree base/
base/
├── a
│   ├── 1
│   └── 2
└── b
    ├── 1
    └── 2

Why Bracex over other solutions?

Bracex actually follows pretty closely to how Bash processes braces. It is not a 1:1 implementation of how Bash handles braces, but generally, it follows very closely. Almost all of the test cases are run through Bash first, then our implementation is compared against the results Bash gives. There are a few cases where we have purposely deviated. For instance, we are not handling Bash's command line inputs, so we are not giving special meaning to back ticks and quotes at this time.

On the command line Bracex can handle more expansions than Bash itself.