built-in functions and exceptions object(the base class for all objects in python you can call it to create an instancebut the result isn' especially interesting oct(xconverts an integerxto an octal string open(filename [mode [bufsize]]in python opens the file filename and returns new file object (refer to "input and output"mode is string that indicates how the file should be opened'rfor reading'wfor writingand 'afor appending second character 'tor 'bis used to indicate text-mode (the defaultor binary mode for example'ror 'rtopens file in text modewhereas 'rbopens file in binary mode an optional '+can be added to the mode to open the file for updating (which allows both reading and writinga mode of ' +truncates the file to zero length if it already exists mode of ' +or ' +opens the file for both reading and writing but leaves the original contents intact when the file is opened if mode of 'uor 'ruis specifiedthe file is opened in universal newline mode in this modeall variants of newline ('\ ''\ ''\ \ 'are converted to the standard '\ncharacter if the mode is omitteda mode of 'rtis assumed the bufsize argument specifies the buffering behaviorwhere is unbuffered is line bufferedand any other positive number indicates an approximate buffer size in bytes negative number indicates that the system default buffering should be used (this is the default behavioropen(filename [mode [bufsize [encoding [errors [newline [closefd]]]]]]in python this opens the file filename and returns file object the first three arguments have the same meaning as for the python version of open(described earlier encoding is an encoding name such as 'utf- errors is the error handling policy and is one of 'strict''ignore''replace''backslashreplace'or 'xmlcharrefreplacenewline controls the behavior of universal newline mode and is set to none'''\ ''\ 'or '\ \nclosefd is boolean flag that specifies whether the underlying file descriptor is closed when the close(method executes unlike python different kinds of objects are returned depending on the selected / mode for exampleif you open file in binary modeyou get an object where / operations such as read(and write(operate on byte arrays instead of strings file / is one area where there are significant differences between python and consult appendix "python ,for more details ord(creturns the integer ordinal value of single characterc for ordinary charactersa value in the range [ , is returned for single unicode charactersa value in the range [ , is usually returned in python may also be unicode surrogate pairin which case it is converted into the appropriate unicode code point pow(xy [ ]returns * if is suppliedthis function returns ( *yz if all three arguments are giventhey must be integers and must be nonnegative lib fl ff