String conversion and formatting

• int PyOS_snprintf(char *str, size_t size, const char *format, ...)

• int PyOS_vsnprintf(char *str, size_t size, const char *format, va_list va)

• double PyOS_string_to_double(const char *s, char **endptr, PyObject *overflow_exception)

• char *PyOS_double_to_string(double val, char format_code, int precision, int flags, int *ptype)

• int PyOS_stricmp(const char *s1, const char *s2)

• int PyOS_strnicmp(const char *s1, const char *s2, Py_ssize_t size)