mpl.mathtext.ParserElement.setFailAction¶

ParserElement.setFailAction(fn)[source]¶

Define action to perform if parsing fails at this expression. Fail acton fn is a callable function that takes the arguments C{fn(s,loc,expr,err)} where:

• s = string being parsed
• loc = location where expression match was attempted and failed
• expr = the parse expression that failed
• err = the exception thrown

The function returns no value. It may throw C{L{ParseFatalException}} if it is desired to stop parsing immediately.