summaryrefslogtreecommitdiffstats
path: root/Doc/ref
diff options
context:
space:
mode:
Diffstat (limited to 'Doc/ref')
-rw-r--r--Doc/ref/ref3.tex5
-rw-r--r--Doc/ref/ref7.tex15
2 files changed, 17 insertions, 3 deletions
diff --git a/Doc/ref/ref3.tex b/Doc/ref/ref3.tex
index df62486..855dc82 100644
--- a/Doc/ref/ref3.tex
+++ b/Doc/ref/ref3.tex
@@ -532,12 +532,13 @@ the code object).
\ttindex{f_lineno}
\ttindex{f_lasti}
-\item[Traceback objects]
+\item[Traceback objects] \label{traceback}
Traceback objects represent a stack trace of an exception. A
traceback object is created when an exception occurs. When the search
for an exception handler unwinds the execution stack, at each unwound
level a traceback object is inserted in front of the current
-traceback. When an exception handler is entered, the stack trace is
+traceback. When an exception handler is entered
+(see also section \ref{try}), the stack trace is
made available to the program as \verb\sys.exc_traceback\. When the
program contains no suitable handler, the stack trace is written
(nicely formatted) to the standard error stream; if the interpreter is
diff --git a/Doc/ref/ref7.tex b/Doc/ref/ref7.tex
index 357bd5f..0f96c82 100644
--- a/Doc/ref/ref7.tex
+++ b/Doc/ref/ref7.tex
@@ -172,7 +172,7 @@ for x in a[:]:
if x < 0: a.remove(x)
\end{verbatim}
-\section{The {\tt try} statement}
+\section{The {\tt try} statement} \label{try}
\stindex{try}
The \verb\try\ statement specifies exception handlers and/or cleanup
@@ -222,6 +222,19 @@ statement. (This means that if two nested handlers exist for the same
exception, and the exception occurs in the try clause of the inner
handler, the outer handler will not handle the exception.)
+Before an except clause's suite is executed, details about the
+exception are assigned to three variables in the \verb\sys\ module:
+\verb\sys.exc_type\ receives the object identifying the exception;
+\verb\sys.exc_value\ receives the exception's parameter;
+\verb\sys.exc_traceback\ receives a traceback object (see section
+\ref{traceback}) identifying the point in the program where the
+exception occurred.
+\bimodindex{sys}
+\ttindex{exc_type}
+\ttindex{exc_value}
+\ttindex{exc_traceback}
+\obindex{traceback}
+
The \verb\try...finally\ form specifies a `cleanup' handler. The
\verb\try\ clause is executed. When no exception occurs, the
\verb\finally\ clause is executed. When an exception occurs in the