Python\u2019s built-in library has an os module that provides useful operating system-dependent functions. It also provides functions for performing low-level read\/write operations on the file. Let us briefly get acquainted with them.<\/p>\n
The open ()<\/strong> function from the os module (obviously it needs to be referred to as os. open ( ))<\/strong> is similar to the built-in open ( )<\/strong> function in the sense it also opens a file for reading\/write operations. However, it doesn\u2019t return a file or file-like object but a file descriptor, an integer corresponding to the file opened. File descriptor\u2019s values 0, 1, and 2 are reserved for stdin,<\/strong> stout<\/strong>, and stder r<\/strong> streams. Other files will be given an incremental file descriptor. Also, the write ( )<\/strong> and read( )<\/strong> functions of the os module needs bytes to object as the argument. The os .open ()<\/strong> function needs to be provided one or combinations of the following constants: (Table 5.2)<\/p>\n\n\n
\n os.OWRONLY<\/td>\n open for writing only<\/td>\n<\/tr>\n \n os.ORDWR<\/td>\n open for reading and writing<\/td>\n<\/tr>\n \n os.OAPPEND<\/td>\n append on each write<\/td>\n<\/tr>\n \n os.OCREAT<\/td>\n create file if it does not exist<\/td>\n<\/tr>\n \n os.OTRUNC<\/td>\n truncate size to 0<\/td>\n<\/tr>\n \n os.OEXCL<\/td>\n error if create and file exists<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n