Regex replace should mention $ escaping is only for substitution

[orlp]

Description

The docs for Expr.str.replace should be improved, they are confusing because they state the following:

The dollar sign ($) is a special character related to capture groups. To refer to a literal dollar sign, use $$ instead or set literal to True.

This only applies to the replacement, not the pattern. In a pattern $ must be escaped using a backslash: "\\$". This was confusing for this user: #19523.

Link

https://docs.pola.rs/api/python/stable/reference/expressions/api/polars.Expr.str.replace.html

[alexander-beedie]

Yup; almost finished an update for this.