4.4 Interpreting Error Messages

     

One of Python's unique features is the level of source location information it provides in error messages. The error messages contain a lot of detail in a terse format, to they may be confusing at first. Error messages will be illustrated using this example program:

(defmacro zoq (x)
  `(roq (ploq (+ ,x 3))))

(defun foo (y)
  (declare (symbol y))
  (zoq y))

The main problem with this program is that it is trying to add 3 to a symbol. Note also that the functions roq and ploq aren't defined anywhere.

 
• 4.4.1 The Parts of the Error Message
• 4.4.2 The Original and Actual Source
• 4.4.3 The Processing Path
• 4.4.4 Error Severity
• 4.4.5 Errors During Macroexpansion
• 4.4.6 Read Errors
• 4.4.7 Error Message Parameterization