Functions for number conversion and formatted string output.
:cfunc:`PyOS_snprintf` and :cfunc:`PyOS_vsnprintf` wrap the Standard C library functions :cfunc:`snprintf` and :cfunc:`vsnprintf`. Their purpose is to guarantee consistent behavior in corner cases, which the Standard C functions do not.
The wrappers ensure that str*[*size-1] is always '\0' upon return. They never write more than size bytes (including the trailing '\0' into str. Both functions require that str != NULL, size > 0 and format != NULL.
If the platform doesn’t have :cfunc:`vsnprintf` and the buffer size needed to avoid truncation exceeds size by more than 512 bytes, Python aborts with a Py_FatalError.
The return value (rv) for these functions should be interpreted as follows:
The following functions provide locale-independent string to number conversions.