help(os)
    Help on module os:

    NAME
    os - OS routines for NT or Posix depending on what system we’re on.

    MODULE REFERENCE
    https://docs.python.org/3.9/library/os

    1. The following documentation is automatically generated from the Python<br />    source files.  It may be incomplete, incorrect or include features that<br />    are considered implementation detail and may vary between Python<br />    implementations.  When in doubt, consult the module reference at the<br />    location listed above.

    DESCRIPTION
    This exports:
    - all functions from posix or nt, e.g. unlink, stat, etc.
    - os.path is either posixpath or ntpath
    - os.name is either ‘posix’ or ‘nt’
    - os.curdir is a string representing the current directory (always ‘.’)
    - os.pardir is a string representing the parent directory (always ‘..’)
    - os.sep is the (or a most common) pathname separator (‘/‘ or ‘\‘)
    - os.extsep is the extension separator (always ‘.’)
    - os.altsep is the alternate pathname separator (None or ‘/‘)
    - os.pathsep is the component separator used in $PATH etc
    - os.linesep is the line separator in text files (‘\r’ or ‘\n’ or ‘\r\n’)
    - os.defpath is the default search path for executables
    - os.devnull is the file path of the null device (‘/dev/null’, etc.)

    Programs that import and use 'os' stand a better chance of being<br />    portable between different platforms.  Of course, they must then<br />    only use functions that are defined by all platforms (e.g., unlink<br />    and opendir), and leave all pathname manipulation to os.path<br />    (e.g., split and join).

    CLASSES
    builtins.Exception(builtins.BaseException)
    builtins.OSError
    builtins.object
    nt.DirEntry
    builtins.tuple(builtins.object)
    nt.times_result
    nt.uname_result
    stat_result
    statvfs_result
    terminal_size

    class DirEntry(builtins.object)<br />     |  Methods defined here:<br />     |<br />     |  __fspath__(self, /)<br />     |      Returns the path for the entry.<br />     |<br />     |  __repr__(self, /)<br />     |      Return repr(self).<br />     |<br />     |  inode(self, /)<br />     |      Return inode of the entry; cached per entry.<br />     |<br />     |  is_dir(self, /, *, follow_symlinks=True)<br />     |      Return True if the entry is a directory; cached per entry.<br />     |<br />     |  is_file(self, /, *, follow_symlinks=True)<br />     |      Return True if the entry is a file; cached per entry.<br />     |<br />     |  is_symlink(self, /)<br />     |      Return True if the entry is a symbolic link; cached per entry.<br />     |<br />     |  stat(self, /, *, follow_symlinks=True)<br />     |      Return stat_result object for the entry; cached per entry.<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Class methods defined here:<br />     |<br />     |  __class_getitem__(...) from builtins.type<br />     |      See PEP 585<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Static methods defined here:<br />     |<br />     |  __new__(*args, **kwargs) from builtins.type<br />     |      Create and return a new object.  See help(type) for accurate signature.<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Data descriptors defined here:<br />     |<br />     |  name<br />     |      the entry's base filename, relative to scandir() "path" argument<br />     |<br />     |  path<br />     |      the entry's full path name; equivalent to os.path.join(scandir_path, entry.name)

error = class OSError(Exception)<br />     |  Base class for I/O related errors.<br />     |<br />     |  Method resolution order:<br />     |      OSError<br />     |      Exception<br />     |      BaseException<br />     |      object<br />     |<br />     |  Built-in subclasses:<br />     |      BlockingIOError<br />     |      ChildProcessError<br />     |      ConnectionError<br />     |      FileExistsError<br />     |      ... and 7 other subclasses<br />     |<br />     |  Methods defined here:<br />     |<br />     |  __init__(self, /, *args, **kwargs)<br />     |      Initialize self.  See help(type(self)) for accurate signature.<br />     |<br />     |  __reduce__(...)<br />     |      Helper for pickle.<br />     |<br />     |  __str__(self, /)<br />     |      Return str(self).<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Static methods defined here:<br />     |<br />     |  __new__(*args, **kwargs) from builtins.type<br />     |      Create and return a new object.  See help(type) for accurate signature.<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Data descriptors defined here:<br />     |<br />     |  characters_written<br />     |<br />     |  errno<br />     |      POSIX exception code<br />     |<br />     |  filename<br />     |      exception filename<br />     |<br />     |  filename2<br />     |      second exception filename<br />     |<br />     |  strerror<br />     |      exception strerror<br />     |<br />     |  winerror<br />     |      Win32 exception code<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Methods inherited from BaseException:<br />     |<br />     |  __delattr__(self, name, /)<br />     |      Implement delattr(self, name).<br />     |<br />     |  __getattribute__(self, name, /)<br />     |      Return getattr(self, name).<br />     |<br />     |  __repr__(self, /)<br />     |      Return repr(self).<br />     |<br />     |  __setattr__(self, name, value, /)<br />     |      Implement setattr(self, name, value).<br />     |<br />     |  __setstate__(...)<br />     |<br />     |  with_traceback(...)<br />     |      Exception.with_traceback(tb) --<br />     |      set self.__traceback__ to tb and return self.<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Data descriptors inherited from BaseException:<br />     |<br />     |  __cause__<br />     |      exception cause<br />     |<br />     |  __context__<br />     |      exception context<br />     |<br />     |  __dict__<br />     |<br />     |  __suppress_context__<br />     |<br />     |  __traceback__<br />     |<br />     |  args

class stat_result(builtins.tuple)<br />     |  stat_result(iterable=(), /)<br />     |<br />     |  stat_result: Result from stat, fstat, or lstat.<br />     |<br />     |  This object may be accessed either as a tuple of<br />     |    (mode, ino, dev, nlink, uid, gid, size, atime, mtime, ctime)<br />     |  or via the attributes st_mode, st_ino, st_dev, st_nlink, st_uid, and so on.<br />     |<br />     |  Posix/windows: If your platform supports st_blksize, st_blocks, st_rdev,<br />     |  or st_flags, they are available as attributes only.<br />     |<br />     |  See os.stat for more information.<br />     |<br />     |  Method resolution order:<br />     |      stat_result<br />     |      builtins.tuple<br />     |      builtins.object<br />     |<br />     |  Methods defined here:<br />     |<br />     |  __reduce__(...)<br />     |      Helper for pickle.<br />     |<br />     |  __repr__(self, /)<br />     |      Return repr(self).<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Static methods defined here:<br />     |<br />     |  __new__(*args, **kwargs) from builtins.type<br />     |      Create and return a new object.  See help(type) for accurate signature.<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Data descriptors defined here:<br />     |<br />     |  st_atime<br />     |      time of last access<br />     |<br />     |  st_atime_ns<br />     |      time of last access in nanoseconds<br />     |<br />     |  st_ctime<br />     |      time of last change<br />     |<br />     |  st_ctime_ns<br />     |      time of last change in nanoseconds<br />     |<br />     |  st_dev<br />     |      device<br />     |<br />     |  st_file_attributes<br />     |      Windows file attribute bits<br />     |<br />     |  st_gid<br />     |      group ID of owner<br />     |<br />     |  st_ino<br />     |      inode<br />     |<br />     |  st_mode<br />     |      protection bits<br />     |<br />     |  st_mtime<br />     |      time of last modification<br />     |<br />     |  st_mtime_ns<br />     |      time of last modification in nanoseconds<br />     |<br />     |  st_nlink<br />     |      number of hard links<br />     |<br />     |  st_reparse_tag<br />     |      Windows reparse tag<br />     |<br />     |  st_size<br />     |      total size, in bytes<br />     |<br />     |  st_uid<br />     |      user ID of owner<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Data and other attributes defined here:<br />     |<br />     |  n_fields = 18<br />     |<br />     |  n_sequence_fields = 10<br />     |<br />     |  n_unnamed_fields = 3<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Methods inherited from builtins.tuple:<br />     |<br />     |  __add__(self, value, /)<br />     |      Return self+value.<br />     |<br />     |  __contains__(self, key, /)<br />     |      Return key in self.<br />     |<br />     |  __eq__(self, value, /)<br />     |      Return self==value.<br />     |<br />     |  __ge__(self, value, /)<br />     |      Return self>=value.<br />     |<br />     |  __getattribute__(self, name, /)<br />     |      Return getattr(self, name).<br />     |<br />     |  __getitem__(self, key, /)<br />     |      Return self[key].<br />     |<br />     |  __getnewargs__(self, /)<br />     |<br />     |  __gt__(self, value, /)<br />     |      Return self>value.<br />     |<br />     |  __hash__(self, /)<br />     |      Return hash(self).<br />     |<br />     |  __iter__(self, /)<br />     |      Implement iter(self).<br />     |<br />     |  __le__(self, value, /)<br />     |      Return self<=value.<br />     |<br />     |  __len__(self, /)<br />     |      Return len(self).<br />     |<br />     |  __lt__(self, value, /)<br />     |      Return self<value.<br />     |<br />     |  __mul__(self, value, /)<br />     |      Return self*value.<br />     |<br />     |  __ne__(self, value, /)<br />     |      Return self!=value.<br />     |<br />     |  __rmul__(self, value, /)<br />     |      Return value*self.<br />     |<br />     |  count(self, value, /)<br />     |      Return number of occurrences of value.<br />     |<br />     |  index(self, value, start=0, stop=9223372036854775807, /)<br />     |      Return first index of value.<br />     |<br />     |      Raises ValueError if the value is not present.<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Class methods inherited from builtins.tuple:<br />     |<br />     |  __class_getitem__(...) from builtins.type<br />     |      See PEP 585

class statvfs_result(builtins.tuple)<br />     |  statvfs_result(iterable=(), /)<br />     |<br />     |  statvfs_result: Result from statvfs or fstatvfs.<br />     |<br />     |  This object may be accessed either as a tuple of<br />     |    (bsize, frsize, blocks, bfree, bavail, files, ffree, favail, flag, namemax),<br />     |  or via the attributes f_bsize, f_frsize, f_blocks, f_bfree, and so on.<br />     |<br />     |  See os.statvfs for more information.<br />     |<br />     |  Method resolution order:<br />     |      statvfs_result<br />     |      builtins.tuple<br />     |      builtins.object<br />     |<br />     |  Methods defined here:<br />     |<br />     |  __reduce__(...)<br />     |      Helper for pickle.<br />     |<br />     |  __repr__(self, /)<br />     |      Return repr(self).<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Static methods defined here:<br />     |<br />     |  __new__(*args, **kwargs) from builtins.type<br />     |      Create and return a new object.  See help(type) for accurate signature.<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Data descriptors defined here:<br />     |<br />     |  f_bavail<br />     |<br />     |  f_bfree<br />     |<br />     |  f_blocks<br />     |<br />     |  f_bsize<br />     |<br />     |  f_favail<br />     |<br />     |  f_ffree<br />     |<br />     |  f_files<br />     |<br />     |  f_flag<br />     |<br />     |  f_frsize<br />     |<br />     |  f_fsid<br />     |<br />     |  f_namemax<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Data and other attributes defined here:<br />     |<br />     |  n_fields = 11<br />     |<br />     |  n_sequence_fields = 10<br />     |<br />     |  n_unnamed_fields = 0<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Methods inherited from builtins.tuple:<br />     |<br />     |  __add__(self, value, /)<br />     |      Return self+value.<br />     |<br />     |  __contains__(self, key, /)<br />     |      Return key in self.<br />     |<br />     |  __eq__(self, value, /)<br />     |      Return self==value.<br />     |<br />     |  __ge__(self, value, /)<br />     |      Return self>=value.<br />     |<br />     |  __getattribute__(self, name, /)<br />     |      Return getattr(self, name).<br />     |<br />     |  __getitem__(self, key, /)<br />     |      Return self[key].<br />     |<br />     |  __getnewargs__(self, /)<br />     |<br />     |  __gt__(self, value, /)<br />     |      Return self>value.<br />     |<br />     |  __hash__(self, /)<br />     |      Return hash(self).<br />     |<br />     |  __iter__(self, /)<br />     |      Implement iter(self).<br />     |<br />     |  __le__(self, value, /)<br />     |      Return self<=value.<br />     |<br />     |  __len__(self, /)<br />     |      Return len(self).<br />     |<br />     |  __lt__(self, value, /)<br />     |      Return self<value.<br />     |<br />     |  __mul__(self, value, /)<br />     |      Return self*value.<br />     |<br />     |  __ne__(self, value, /)<br />     |      Return self!=value.<br />     |<br />     |  __rmul__(self, value, /)<br />     |      Return value*self.<br />     |<br />     |  count(self, value, /)<br />     |      Return number of occurrences of value.<br />     |<br />     |  index(self, value, start=0, stop=9223372036854775807, /)<br />     |      Return first index of value.<br />     |<br />     |      Raises ValueError if the value is not present.<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Class methods inherited from builtins.tuple:<br />     |<br />     |  __class_getitem__(...) from builtins.type<br />     |      See PEP 585

class terminal_size(builtins.tuple)<br />     |  terminal_size(iterable=(), /)<br />     |<br />     |  A tuple of (columns, lines) for holding terminal window size<br />     |<br />     |  Method resolution order:<br />     |      terminal_size<br />     |      builtins.tuple<br />     |      builtins.object<br />     |<br />     |  Methods defined here:<br />     |<br />     |  __reduce__(...)<br />     |      Helper for pickle.<br />     |<br />     |  __repr__(self, /)<br />     |      Return repr(self).<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Static methods defined here:<br />     |<br />     |  __new__(*args, **kwargs) from builtins.type<br />     |      Create and return a new object.  See help(type) for accurate signature.<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Data descriptors defined here:<br />     |<br />     |  columns<br />     |      width of the terminal window in characters<br />     |<br />     |  lines<br />     |      height of the terminal window in characters<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Data and other attributes defined here:<br />     |<br />     |  n_fields = 2<br />     |<br />     |  n_sequence_fields = 2<br />     |<br />     |  n_unnamed_fields = 0<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Methods inherited from builtins.tuple:<br />     |<br />     |  __add__(self, value, /)<br />     |      Return self+value.<br />     |<br />     |  __contains__(self, key, /)<br />     |      Return key in self.<br />     |<br />     |  __eq__(self, value, /)<br />     |      Return self==value.<br />     |<br />     |  __ge__(self, value, /)<br />     |      Return self>=value.<br />     |<br />     |  __getattribute__(self, name, /)<br />     |      Return getattr(self, name).<br />     |<br />     |  __getitem__(self, key, /)<br />     |      Return self[key].<br />     |<br />     |  __getnewargs__(self, /)<br />     |<br />     |  __gt__(self, value, /)<br />     |      Return self>value.<br />     |<br />     |  __hash__(self, /)<br />     |      Return hash(self).<br />     |<br />     |  __iter__(self, /)<br />     |      Implement iter(self).<br />     |<br />     |  __le__(self, value, /)<br />     |      Return self<=value.<br />     |<br />     |  __len__(self, /)<br />     |      Return len(self).<br />     |<br />     |  __lt__(self, value, /)<br />     |      Return self<value.<br />     |<br />     |  __mul__(self, value, /)<br />     |      Return self*value.<br />     |<br />     |  __ne__(self, value, /)<br />     |      Return self!=value.<br />     |<br />     |  __rmul__(self, value, /)<br />     |      Return value*self.<br />     |<br />     |  count(self, value, /)<br />     |      Return number of occurrences of value.<br />     |<br />     |  index(self, value, start=0, stop=9223372036854775807, /)<br />     |      Return first index of value.<br />     |<br />     |      Raises ValueError if the value is not present.<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Class methods inherited from builtins.tuple:<br />     |<br />     |  __class_getitem__(...) from builtins.type<br />     |      See PEP 585

class times_result(builtins.tuple)<br />     |  times_result(iterable=(), /)<br />     |<br />     |  times_result: Result from os.times().<br />     |<br />     |  This object may be accessed either as a tuple of<br />     |    (user, system, children_user, children_system, elapsed),<br />     |  or via the attributes user, system, children_user, children_system,<br />     |  and elapsed.<br />     |<br />     |  See os.times for more information.<br />     |<br />     |  Method resolution order:<br />     |      times_result<br />     |      builtins.tuple<br />     |      builtins.object<br />     |<br />     |  Methods defined here:<br />     |<br />     |  __reduce__(...)<br />     |      Helper for pickle.<br />     |<br />     |  __repr__(self, /)<br />     |      Return repr(self).<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Static methods defined here:<br />     |<br />     |  __new__(*args, **kwargs) from builtins.type<br />     |      Create and return a new object.  See help(type) for accurate signature.<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Data descriptors defined here:<br />     |<br />     |  children_system<br />     |      system time of children<br />     |<br />     |  children_user<br />     |      user time of children<br />     |<br />     |  elapsed<br />     |      elapsed time since an arbitrary point in the past<br />     |<br />     |  system<br />     |      system time<br />     |<br />     |  user<br />     |      user time<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Data and other attributes defined here:<br />     |<br />     |  n_fields = 5<br />     |<br />     |  n_sequence_fields = 5<br />     |<br />     |  n_unnamed_fields = 0<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Methods inherited from builtins.tuple:<br />     |<br />     |  __add__(self, value, /)<br />     |      Return self+value.<br />     |<br />     |  __contains__(self, key, /)<br />     |      Return key in self.<br />     |<br />     |  __eq__(self, value, /)<br />     |      Return self==value.<br />     |<br />     |  __ge__(self, value, /)<br />     |      Return self>=value.<br />     |<br />     |  __getattribute__(self, name, /)<br />     |      Return getattr(self, name).<br />     |<br />     |  __getitem__(self, key, /)<br />     |      Return self[key].<br />     |<br />     |  __getnewargs__(self, /)<br />     |<br />     |  __gt__(self, value, /)<br />     |      Return self>value.<br />     |<br />     |  __hash__(self, /)<br />     |      Return hash(self).<br />     |<br />     |  __iter__(self, /)<br />     |      Implement iter(self).<br />     |<br />     |  __le__(self, value, /)<br />     |      Return self<=value.<br />     |<br />     |  __len__(self, /)<br />     |      Return len(self).<br />     |<br />     |  __lt__(self, value, /)<br />     |      Return self<value.<br />     |<br />     |  __mul__(self, value, /)<br />     |      Return self*value.<br />     |<br />     |  __ne__(self, value, /)<br />     |      Return self!=value.<br />     |<br />     |  __rmul__(self, value, /)<br />     |      Return value*self.<br />     |<br />     |  count(self, value, /)<br />     |      Return number of occurrences of value.<br />     |<br />     |  index(self, value, start=0, stop=9223372036854775807, /)<br />     |      Return first index of value.<br />     |<br />     |      Raises ValueError if the value is not present.<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Class methods inherited from builtins.tuple:<br />     |<br />     |  __class_getitem__(...) from builtins.type<br />     |      See PEP 585

class uname_result(builtins.tuple)<br />     |  uname_result(iterable=(), /)<br />     |<br />     |  uname_result: Result from os.uname().<br />     |<br />     |  This object may be accessed either as a tuple of<br />     |    (sysname, nodename, release, version, machine),<br />     |  or via the attributes sysname, nodename, release, version, and machine.<br />     |<br />     |  See os.uname for more information.<br />     |<br />     |  Method resolution order:<br />     |      uname_result<br />     |      builtins.tuple<br />     |      builtins.object<br />     |<br />     |  Methods defined here:<br />     |<br />     |  __reduce__(...)<br />     |      Helper for pickle.<br />     |<br />     |  __repr__(self, /)<br />     |      Return repr(self).<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Static methods defined here:<br />     |<br />     |  __new__(*args, **kwargs) from builtins.type<br />     |      Create and return a new object.  See help(type) for accurate signature.<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Data descriptors defined here:<br />     |<br />     |  machine<br />     |      hardware identifier<br />     |<br />     |  nodename<br />     |      name of machine on network (implementation-defined)<br />     |<br />     |  release<br />     |      operating system release<br />     |<br />     |  sysname<br />     |      operating system name<br />     |<br />     |  version<br />     |      operating system version<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Data and other attributes defined here:<br />     |<br />     |  n_fields = 5<br />     |<br />     |  n_sequence_fields = 5<br />     |<br />     |  n_unnamed_fields = 0<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Methods inherited from builtins.tuple:<br />     |<br />     |  __add__(self, value, /)<br />     |      Return self+value.<br />     |<br />     |  __contains__(self, key, /)<br />     |      Return key in self.<br />     |<br />     |  __eq__(self, value, /)<br />     |      Return self==value.<br />     |<br />     |  __ge__(self, value, /)<br />     |      Return self>=value.<br />     |<br />     |  __getattribute__(self, name, /)<br />     |      Return getattr(self, name).<br />     |<br />     |  __getitem__(self, key, /)<br />     |      Return self[key].<br />     |<br />     |  __getnewargs__(self, /)<br />     |<br />     |  __gt__(self, value, /)<br />     |      Return self>value.<br />     |<br />     |  __hash__(self, /)<br />     |      Return hash(self).<br />     |<br />     |  __iter__(self, /)<br />     |      Implement iter(self).<br />     |<br />     |  __le__(self, value, /)<br />     |      Return self<=value.<br />     |<br />     |  __len__(self, /)<br />     |      Return len(self).<br />     |<br />     |  __lt__(self, value, /)<br />     |      Return self<value.<br />     |<br />     |  __mul__(self, value, /)<br />     |      Return self*value.<br />     |<br />     |  __ne__(self, value, /)<br />     |      Return self!=value.<br />     |<br />     |  __rmul__(self, value, /)<br />     |      Return value*self.<br />     |<br />     |  count(self, value, /)<br />     |      Return number of occurrences of value.<br />     |<br />     |  index(self, value, start=0, stop=9223372036854775807, /)<br />     |      Return first index of value.<br />     |<br />     |      Raises ValueError if the value is not present.<br />     |<br />     |  ----------------------------------------------------------------------<br />     |  Class methods inherited from builtins.tuple:<br />     |<br />     |  __class_getitem__(...) from builtins.type<br />     |      See PEP 585

    FUNCTIONS
    _exit(status)
    Exit to the system with specified status, without normal exit processing.

    abort()<br />        Abort the interpreter immediately.

    This function 'dumps core' or otherwise fails in the hardest way possible<br />        on the hosting operating system.  This function never returns.

access(path, mode, *, dir_fd=None, effective_ids=False, follow_symlinks=True)<br />        Use the real uid/gid to test for access to a path.

      path<br />            Path to be tested; can be string, bytes, or a path-like object.<br />          mode<br />            Operating-system mode bitfield.  Can be F_OK to test existence,<br />            or the inclusive-OR of R_OK, W_OK, and X_OK.<br />          dir_fd<br />            If not None, it should be a file descriptor open to a directory,<br />            and path should be relative; path will then be relative to that<br />            directory.<br />          effective_ids<br />            If True, access will use the effective uid/gid instead of<br />            the real uid/gid.<br />          follow_symlinks<br />            If False, and the last element of the path is a symbolic link,<br />            access will examine the symbolic link itself instead of the file<br />            the link points to.

    dir_fd, effective_ids, and follow_symlinks may not be implemented<br />          on your platform.  If they are unavailable, using them will raise a<br />          NotImplementedError.

    Note that most operations will use the effective uid/gid, therefore this<br />          routine can be used in a suid/sgid environment to test if the invoking user<br />          has the specified access to the path.

chdir(path)<br />        Change the current working directory to the specified path.

    path may always be specified as a string.<br />        On some platforms, path may also be specified as an open file descriptor.<br />          If this functionality is unavailable, using it raises an exception.

chmod(path, mode, *, dir_fd=None, follow_symlinks=True)<br />        Change the access permissions of a file.

      path<br />            Path to be modified.  May always be specified as a str, bytes, or a path-like object.<br />            On some platforms, path may also be specified as an open file descriptor.<br />            If this functionality is unavailable, using it raises an exception.<br />          mode<br />            Operating-system mode bitfield.<br />          dir_fd<br />            If not None, it should be a file descriptor open to a directory,<br />            and path should be relative; path will then be relative to that<br />            directory.<br />          follow_symlinks<br />            If False, and the last element of the path is a symbolic link,<br />            chmod will modify the symbolic link itself instead of the file<br />            the link points to.

    It is an error to use dir_fd or follow_symlinks when specifying path as<br />          an open file descriptor.<br />        dir_fd and follow_symlinks may not be implemented on your platform.<br />          If they are unavailable, using them will raise a NotImplementedError.

close(fd)<br />        Close a file descriptor.

closerange(fd_low, fd_high, /)<br />        Closes all file descriptors in [fd_low, fd_high), ignoring errors.

cpu_count()<br />        Return the number of CPUs in the system; return None if indeterminable.

    This number is not equivalent to the number of CPUs the current process can<br />        use.  The number of usable CPUs can be obtained with<br />        ``len(os.sched_getaffinity(0))``

device_encoding(fd)<br />        Return a string describing the encoding of a terminal's file descriptor.

    The file descriptor must be attached to a terminal.<br />        If the device is not a terminal, return None.

dup(fd, /)<br />        Return a duplicate of a file descriptor.

dup2(fd, fd2, inheritable=True)<br />        Duplicate file descriptor.

execl(file, *args)<br />        execl(file, *args)

    Execute the executable file with argument list args, replacing the<br />        current process.

execle(file, *args)<br />        execle(file, *args, env)

    Execute the executable file with argument list args and<br />        environment env, replacing the current process.

execlp(file, *args)<br />        execlp(file, *args)

    Execute the executable file (which is searched for along $PATH)<br />        with argument list args, replacing the current process.

execlpe(file, *args)<br />        execlpe(file, *args, env)

    Execute the executable file (which is searched for along $PATH)<br />        with argument list args and environment env, replacing the current<br />        process.

execv(path, argv, /)<br />        Execute an executable path with arguments, replacing current process.

    path<br />          Path of executable file.<br />        argv<br />          Tuple or list of strings.

execve(path, argv, env)<br />        Execute an executable path with arguments, replacing current process.

    path<br />          Path of executable file.<br />        argv<br />          Tuple or list of strings.<br />        env<br />          Dictionary of strings mapping to strings.

execvp(file, args)<br />        execvp(file, args)

    Execute the executable file (which is searched for along $PATH)<br />        with argument list args, replacing the current process.<br />        args may be a list or tuple of strings.

execvpe(file, args, env)<br />        execvpe(file, args, env)

    Execute the executable file (which is searched for along $PATH)<br />        with argument list args and environment env, replacing the<br />        current process.<br />        args may be a list or tuple of strings.

fdopen(fd, *args, **kwargs)<br />        # Supply os.fdopen()

fsdecode(filename)<br />        Decode filename (an os.PathLike, bytes, or str) from the filesystem<br />        encoding with 'surrogateescape' error handler, return str unchanged. On<br />        Windows, use 'strict' error handler if the file system encoding is<br />        'mbcs' (which is the default encoding).

fsencode(filename)<br />        Encode filename (an os.PathLike, bytes, or str) to the filesystem<br />        encoding with 'surrogateescape' error handler, return bytes unchanged.<br />        On Windows, use 'strict' error handler if the file system encoding is<br />        'mbcs' (which is the default encoding).

fspath(path)<br />        Return the file system path representation of the object.

    If the object is str or bytes, then allow it to pass through as-is. If the<br />        object defines __fspath__(), then return the result of that method. All other<br />        types raise a TypeError.

fstat(fd)<br />        Perform a stat system call on the given file descriptor.

    Like stat(), but for an open file descriptor.<br />        Equivalent to os.stat(fd).

fsync(fd)<br />        Force write of fd to disk.

ftruncate(fd, length, /)<br />        Truncate a file, specified by file descriptor, to a specific length.

get_exec_path(env=None)<br />        Returns the sequence of directories that will be searched for the<br />        named executable (similar to a shell) when launching a process.

    *env* must be an environment variable dict or None.  If *env* is None,<br />        os.environ will be used.

get_handle_inheritable(handle, /)<br />        Get the close-on-exe flag of the specified file descriptor.

get_inheritable(fd, /)<br />        Get the close-on-exe flag of the specified file descriptor.

get_terminal_size(...)<br />        Return the size of the terminal window as (columns, lines).

    The optional argument fd (default standard output) specifies<br />        which file descriptor should be queried.

    If the file descriptor is not connected to a terminal, an OSError<br />        is thrown.

    This function will only be defined if an implementation is<br />        available for this system.

    shutil.get_terminal_size is the high-level function which should<br />        normally be used, os.get_terminal_size is the low-level implementation.

getcwd()<br />        Return a unicode string representing the current working directory.

getcwdb()<br />        Return a bytes string representing the current working directory.

getenv(key, default=None)<br />        Get an environment variable, return None if it doesn't exist.<br />        The optional second argument can specify an alternate default.<br />        key, default and the result are str.

getlogin()<br />        Return the actual login name.

getpid()<br />        Return the current process id.

getppid()<br />        Return the parent's process id.

    If the parent process has already exited, Windows machines will still<br />        return its id; others systems will return the id of the 'init' process (1).

isatty(fd, /)<br />        Return True if the fd is connected to a terminal.

    Return True if the file descriptor is an open file descriptor<br />        connected to the slave end of a terminal.

kill(pid, signal, /)<br />        Kill a process with a signal.

link(src, dst, *, src_dir_fd=None, dst_dir_fd=None, follow_symlinks=True)<br />        Create a hard link to a file.

    If either src_dir_fd or dst_dir_fd is not None, it should be a file<br />          descriptor open to a directory, and the respective path string (src or dst)<br />          should be relative; the path will then be relative to that directory.<br />        If follow_symlinks is False, and the last element of src is a symbolic<br />          link, link will create a link to the symbolic link itself instead of the<br />          file the link points to.<br />        src_dir_fd, dst_dir_fd, and follow_symlinks may not be implemented on your<br />          platform.  If they are unavailable, using them will raise a<br />          NotImplementedError.

listdir(path=None)<br />        Return a list containing the names of the files in the directory.

    path can be specified as either str, bytes, or a path-like object.  If path is bytes,<br />          the filenames returned will also be bytes; in all other circumstances<br />          the filenames returned will be str.<br />        If path is None, uses the path='.'.<br />        On some platforms, path may also be specified as an open file descriptor;\<br />          the file descriptor must refer to a directory.<br />          If this functionality is unavailable, using it raises NotImplementedError.

    The list is in arbitrary order.  It does not include the special<br />        entries '.' and '..' even if they are present in the directory.

lseek(fd, position, how, /)<br />        Set the position of a file descriptor.  Return the new position.

    Return the new cursor position in number of bytes<br />        relative to the beginning of the file.

lstat(path, *, dir_fd=None)<br />        Perform a stat system call on the given path, without following symbolic links.

    Like stat(), but do not follow symbolic links.<br />        Equivalent to stat(path, follow_symlinks=False).

makedirs(name, mode=511, exist_ok=False)<br />        makedirs(name [, mode=0o777][, exist_ok=False])

    Super-mkdir; create a leaf directory and all intermediate ones.  Works like<br />        mkdir, except that any intermediate path segment (not just the rightmost)<br />        will be created if it does not exist. If the target directory already<br />        exists, raise an OSError if exist_ok is False. Otherwise no exception is<br />        raised.  This is recursive.

mkdir(path, mode=511, *, dir_fd=None)<br />        Create a directory.

    If dir_fd is not None, it should be a file descriptor open to a directory,<br />          and path should be relative; path will then be relative to that directory.<br />        dir_fd may not be implemented on your platform.<br />          If it is unavailable, using it will raise a NotImplementedError.

    The mode argument is ignored on Windows.

open(path, flags, mode=511, *, dir_fd=None)<br />        Open a file for low level IO.  Returns a file descriptor (integer).

    If dir_fd is not None, it should be a file descriptor open to a directory,<br />          and path should be relative; path will then be relative to that directory.<br />        dir_fd may not be implemented on your platform.<br />          If it is unavailable, using it will raise a NotImplementedError.

pipe()<br />        Create a pipe.

    Returns a tuple of two file descriptors:<br />          (read_fd, write_fd)

popen(cmd, mode='r', buffering=-1)<br />        # Supply os.popen()

putenv(name, value, /)<br />        Change or add an environment variable.

read(fd, length, /)<br />        Read from a file descriptor.  Returns a bytes object.

readlink(path, *, dir_fd=None)<br />        Return a string representing the path to which the symbolic link points.

    If dir_fd is not None, it should be a file descriptor open to a directory,<br />        and path should be relative; path will then be relative to that directory.

    dir_fd may not be implemented on your platform.  If it is unavailable,<br />        using it will raise a NotImplementedError.

remove(path, *, dir_fd=None)<br />        Remove a file (same as unlink()).

    If dir_fd is not None, it should be a file descriptor open to a directory,<br />          and path should be relative; path will then be relative to that directory.<br />        dir_fd may not be implemented on your platform.<br />          If it is unavailable, using it will raise a NotImplementedError.

removedirs(name)<br />        removedirs(name)

    Super-rmdir; remove a leaf directory and all empty intermediate<br />        ones.  Works like rmdir except that, if the leaf directory is<br />        successfully removed, directories corresponding to rightmost path<br />        segments will be pruned away until either the whole path is<br />        consumed or an error occurs.  Errors during this latter phase are<br />        ignored -- they generally mean that a directory was not empty.

rename(src, dst, *, src_dir_fd=None, dst_dir_fd=None)<br />        Rename a file or directory.

    If either src_dir_fd or dst_dir_fd is not None, it should be a file<br />          descriptor open to a directory, and the respective path string (src or dst)<br />          should be relative; the path will then be relative to that directory.<br />        src_dir_fd and dst_dir_fd, may not be implemented on your platform.<br />          If they are unavailable, using them will raise a NotImplementedError.

renames(old, new)<br />        renames(old, new)

    Super-rename; create directories as necessary and delete any left<br />        empty.  Works like rename, except creation of any intermediate<br />        directories needed to make the new pathname good is attempted<br />        first.  After the rename, directories corresponding to rightmost<br />        path segments of the old name will be pruned until either the<br />        whole path is consumed or a nonempty directory is found.

    Note: this function can fail with the new directory structure made<br />        if you lack permissions needed to unlink the leaf directory or<br />        file.

replace(src, dst, *, src_dir_fd=None, dst_dir_fd=None)<br />        Rename a file or directory, overwriting the destination.

    If either src_dir_fd or dst_dir_fd is not None, it should be a file<br />          descriptor open to a directory, and the respective path string (src or dst)<br />          should be relative; the path will then be relative to that directory.<br />        src_dir_fd and dst_dir_fd, may not be implemented on your platform.<br />          If they are unavailable, using them will raise a NotImplementedError.

rmdir(path, *, dir_fd=None)<br />        Remove a directory.

    If dir_fd is not None, it should be a file descriptor open to a directory,<br />          and path should be relative; path will then be relative to that directory.<br />        dir_fd may not be implemented on your platform.<br />          If it is unavailable, using it will raise a NotImplementedError.

scandir(path=None)<br />        Return an iterator of DirEntry objects for given path.

    path can be specified as either str, bytes, or a path-like object.  If path<br />        is bytes, the names of yielded DirEntry objects will also be bytes; in<br />        all other circumstances they will be str.

    If path is None, uses the path='.'.

set_handle_inheritable(handle, inheritable, /)<br />        Set the inheritable flag of the specified handle.

set_inheritable(fd, inheritable, /)<br />        Set the inheritable flag of the specified file descriptor.

spawnl(mode, file, *args)<br />        spawnl(mode, file, *args) -> integer

    Execute file with arguments from args in a subprocess.<br />        If mode == P_NOWAIT return the pid of the process.<br />        If mode == P_WAIT return the process's exit code if it exits normally;<br />        otherwise return -SIG, where SIG is the signal that killed it.

spawnle(mode, file, *args)<br />        spawnle(mode, file, *args, env) -> integer

    Execute file with arguments from args in a subprocess with the<br />        supplied environment.<br />        If mode == P_NOWAIT return the pid of the process.<br />        If mode == P_WAIT return the process's exit code if it exits normally;<br />        otherwise return -SIG, where SIG is the signal that killed it.

spawnv(mode, path, argv, /)<br />        Execute the program specified by path in a new process.

    mode<br />          Mode of process creation.<br />        path<br />          Path of executable file.<br />        argv<br />          Tuple or list of strings.

spawnve(mode, path, argv, env, /)<br />        Execute the program specified by path in a new process.

    mode<br />          Mode of process creation.<br />        path<br />          Path of executable file.<br />        argv<br />          Tuple or list of strings.<br />        env<br />          Dictionary of strings mapping to strings.

startfile(...)<br />        Start a file with its associated application.

    When "operation" is not specified or "open", this acts like<br />        double-clicking the file in Explorer, or giving the file name as an<br />        argument to the DOS "start" command: the file is opened with whatever<br />        application (if any) its extension is associated.<br />        When another "operation" is given, it specifies what should be done with<br />        the file.  A typical operation is "print".

    startfile returns as soon as the associated application is launched.<br />        There is no option to wait for the application to close, and no way<br />        to retrieve the application's exit status.

    The filepath is relative to the current directory.  If you want to use<br />        an absolute path, make sure the first character is not a slash ("/");<br />        the underlying Win32 ShellExecute function doesn't work if it is.

stat(path, *, dir_fd=None, follow_symlinks=True)<br />        Perform a stat system call on the given path.

      path<br />            Path to be examined; can be string, bytes, a path-like object or<br />            open-file-descriptor int.<br />          dir_fd<br />            If not None, it should be a file descriptor open to a directory,<br />            and path should be a relative string; path will then be relative to<br />            that directory.<br />          follow_symlinks<br />            If False, and the last element of the path is a symbolic link,<br />            stat will examine the symbolic link itself instead of the file<br />            the link points to.

    dir_fd and follow_symlinks may not be implemented<br />          on your platform.  If they are unavailable, using them will raise a<br />          NotImplementedError.

    It's an error to use dir_fd or follow_symlinks when specifying path as<br />          an open file descriptor.

strerror(code, /)<br />        Translate an error code to a message string.

symlink(src, dst, target_is_directory=False, *, dir_fd=None)<br />        Create a symbolic link pointing to src named dst.

    target_is_directory is required on Windows if the target is to be<br />          interpreted as a directory.  (On Windows, symlink requires<br />          Windows 6.0 or greater, and raises a NotImplementedError otherwise.)<br />          target_is_directory is ignored on non-Windows platforms.

    If dir_fd is not None, it should be a file descriptor open to a directory,<br />          and path should be relative; path will then be relative to that directory.<br />        dir_fd may not be implemented on your platform.<br />          If it is unavailable, using it will raise a NotImplementedError.

system(command)<br />        Execute the command in a subshell.

times()<br />        Return a collection containing process timing information.

    The object returned behaves like a named tuple with these fields:<br />          (utime, stime, cutime, cstime, elapsed_time)<br />        All fields are floating point numbers.

truncate(path, length)<br />        Truncate a file, specified by path, to a specific length.

    On some platforms, path may also be specified as an open file descriptor.<br />          If this functionality is unavailable, using it raises an exception.

umask(mask, /)<br />        Set the current numeric umask and return the previous umask.

unlink(path, *, dir_fd=None)<br />        Remove a file (same as remove()).

    If dir_fd is not None, it should be a file descriptor open to a directory,<br />          and path should be relative; path will then be relative to that directory.<br />        dir_fd may not be implemented on your platform.<br />          If it is unavailable, using it will raise a NotImplementedError.

unsetenv(name, /)<br />        Delete an environment variable.

urandom(size, /)<br />        Return a bytes object containing random bytes suitable for cryptographic use.

utime(...)<br />        Set the access and modified time of path.

    path may always be specified as a string.<br />        On some platforms, path may also be specified as an open file descriptor.<br />          If this functionality is unavailable, using it raises an exception.

    If times is not None, it must be a tuple (atime, mtime);<br />            atime and mtime should be expressed as float seconds since the epoch.<br />        If ns is specified, it must be a tuple (atime_ns, mtime_ns);<br />            atime_ns and mtime_ns should be expressed as integer nanoseconds<br />            since the epoch.<br />        If times is None and ns is unspecified, utime uses the current time.<br />        Specifying tuples for both times and ns is an error.

    If dir_fd is not None, it should be a file descriptor open to a directory,<br />          and path should be relative; path will then be relative to that directory.<br />        If follow_symlinks is False, and the last element of the path is a symbolic<br />          link, utime will modify the symbolic link itself instead of the file the<br />          link points to.<br />        It is an error to use dir_fd or follow_symlinks when specifying path<br />          as an open file descriptor.<br />        dir_fd and follow_symlinks may not be available on your platform.<br />          If they are unavailable, using them will raise a NotImplementedError.

waitpid(pid, options, /)<br />        Wait for completion of a given process.

    Returns a tuple of information regarding the process:<br />            (pid, status << 8)

    The options argument is ignored on Windows.

waitstatus_to_exitcode(status)<br />        Convert a wait status to an exit code.

    On Unix:

    * If WIFEXITED(status) is true, return WEXITSTATUS(status).<br />        * If WIFSIGNALED(status) is true, return -WTERMSIG(status).<br />        * Otherwise, raise a ValueError.

    On Windows, return status shifted right by 8 bits.

    On Unix, if the process is being traced or if waitpid() was called with<br />        WUNTRACED option, the caller must first check if WIFSTOPPED(status) is true.<br />        This function must not be called if WIFSTOPPED(status) is true.

walk(top, topdown=True, onerror=None, followlinks=False)<br />        Directory tree generator.

    For each directory in the directory tree rooted at top (including top<br />        itself, but excluding '.' and '..'), yields a 3-tuple

        dirpath, dirnames, filenames

    dirpath is a string, the path to the directory.  dirnames is a list of<br />        the names of the subdirectories in dirpath (excluding '.' and '..').<br />        filenames is a list of the names of the non-directory files in dirpath.<br />        Note that the names in the lists are just names, with no path components.<br />        To get a full path (which begins with top) to a file or directory in<br />        dirpath, do os.path.join(dirpath, name).

    If optional arg 'topdown' is true or not specified, the triple for a<br />        directory is generated before the triples for any of its subdirectories<br />        (directories are generated top down).  If topdown is false, the triple<br />        for a directory is generated after the triples for all of its<br />        subdirectories (directories are generated bottom up).

    When topdown is true, the caller can modify the dirnames list in-place<br />        (e.g., via del or slice assignment), and walk will only recurse into the<br />        subdirectories whose names remain in dirnames; this can be used to prune the<br />        search, or to impose a specific order of visiting.  Modifying dirnames when<br />        topdown is false has no effect on the behavior of os.walk(), since the<br />        directories in dirnames have already been generated by the time dirnames<br />        itself is generated. No matter the value of topdown, the list of<br />        subdirectories is retrieved before the tuples for the directory and its<br />        subdirectories are generated.

    By default errors from the os.scandir() call are ignored.  If<br />        optional arg 'onerror' is specified, it should be a function; it<br />        will be called with one argument, an OSError instance.  It can<br />        report the error to continue with the walk, or raise the exception<br />        to abort the walk.  Note that the filename is available as the<br />        filename attribute of the exception object.

    By default, os.walk does not follow symbolic links to subdirectories on<br />        systems that support them.  In order to get this functionality, set the<br />        optional argument 'followlinks' to true.

    Caution:  if you pass a relative pathname for top, don't change the<br />        current working directory between resumptions of walk.  walk never<br />        changes the current directory, and assumes that the client doesn't<br />        either.

    Example:

    import os<br />        from os.path import join, getsize<br />        for root, dirs, files in os.walk('python/Lib/email'):<br />            print(root, "consumes", end="")<br />            print(sum(getsize(join(root, name)) for name in files), end="")<br />            print("bytes in", len(files), "non-directory files")<br />            if 'CVS' in dirs:<br />                dirs.remove('CVS')  # don't visit CVS directories

write(fd, data, /)<br />        Write a bytes object to a file descriptor.

    DATA
    FOK = 0
    OAPPEND = 8
    O_BINARY = 32768
    O_CREAT = 256
    O_EXCL = 1024
    O_NOINHERIT = 128
    O_RANDOM = 16
    O_RDONLY = 0
    O_RDWR = 2
    O_SEQUENTIAL = 32
    O_SHORT_LIVED = 4096
    O_TEMPORARY = 64
    O_TEXT = 16384
    O_TRUNC = 512
    O_WRONLY = 1
    P_DETACH = 4
    P_NOWAIT = 1
    P_NOWAITO = 3
    P_OVERLAY = 2
    P_WAIT = 0
    R_OK = 4
    SEEK_CUR = 1
    SEEK_END = 2
    SEEK_SET = 0
    TMP_MAX = 2147483647
    W_OK = 2
    X_OK = 1
    __all     = [‘altsep’, ‘curdir’, ‘pardir’, ‘sep’, ‘pathsep’, ‘linesep’, …
    altsep = ‘/‘
    curdir = ‘.’
    defpath = r’.;C:\bin’
    devnull = ‘nul’
    environ = environ({‘ALLUSERSPROFILE’: ‘C:\ProgramData’, ‘…FILE’: ‘C…
    extsep = ‘.’
    linesep = ‘\r\n’
    name = ‘nt’
    pardir = ‘..’
    pathsep = ‘;’
    sep = r’\’
    supports_bytes_environ = False

    FILE
    d:\python39\lib\os.py

    >