Python Regular Expression Builder (Pyreb) is a wxPython GUI to the re python module. It speeds the development of Python regular expressions (similar to PCRE). The GUI is simple and features three parts, a text box where the text to be analyzed is displayed, a text box where the regular expression to be applied is displayed, and a tree control where the results are displayed When one of the two textboxes change, the regex is compiled and applied. Errors in the regex are shown in a statusbar. Pyreb is somewhat similar to the Activestate RX Toolkit (part of Komodo IDE), but is a completely different project.