diff options
| -rw-r--r-- | Doc/api/api.tex | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/Doc/api/api.tex b/Doc/api/api.tex index 8e7efcb..58188b5 100644 --- a/Doc/api/api.tex +++ b/Doc/api/api.tex @@ -3397,7 +3397,8 @@ function returns true for each pair in the dictionary, and false once all pairs have been reported. The parameters \var{pkey} and \var{pvalue} should either point to \ctype{PyObject*} variables that will be filled in with each key and value, respectively, or may be -\NULL. The dictionary \var{p} must not be mutated during iteration. +\NULL. + For example: \begin{verbatim} @@ -3409,6 +3410,27 @@ while (PyDict_Next(self->dict, &pos, &key, &value)) { ... } \end{verbatim} + +The dictionary \var{p} should not be mutated during iteration. It is +safe (since Python 2.1) to modify the values of the keys as you +iterate over the dictionary, for example: + +\begin{verbatim} +PyObject *key, *value; +int pos = 0; + +while (PyDict_Next(self->dict, &pos, &key, &value)) { + int i = PyInt_AS_LONG(value) + 1; + PyObject *o = PyInt_FromLong(i); + if (o == NULL) + return -1; + if (PyDict_SetItem(self->dict, key, o) < 0) { + Py_DECREF(o); + return -1; + } + Py_DECREF(o); +} +\end{verbatim} \end{cfuncdesc} |