IntelliJ IDEA supports regular expressions of Java flavor. As such, it uses the Java's re module.

When editing source code in a step definition file, note that it is possible to specify data in a step definition as constants, or as regular expressions.

To make IntelliJ IDEA perceive the entered code as a regular expression, ensure the following line is added to the source code of a step definition:

use_step_matcher("re")

So doing, the expressions used in step definitions are perceived as regular expressions:

../../Shared/py_regexp.png

If the matcher is not used, then the expressions in quotes are perceived as strings:

../../Shared/py_noregex.png