os模块包含操作系统功能，类似unix c的api。
主要包含：
def ctermid():
"""Return the filename corresponding to the controlling terminal of the
process.
:rtype: string
"""
return ''
def getegid():
"""Return the effective group id of the current process.
:rtype: int
"""
return 0
def geteuid():
"""Return the current process's effective user id.
:rtype: int
"""
return 0
def getgid():
"""Return the real group id of the current process.
:rtype: int
"""
return 0
def getgroups():
"""Return list of supplemental group ids associated with the current
process.
:rtype: list[int]
"""
return []
def getlogin():
"""Return the name of the user logged in on the controlling terminal of the
process.
:rtype: string
"""
return ''
def getpgid(pid):
"""Return the process group id of the process with process id pid.
:type pid: int
:rtype: int
"""
return 0
def getpgrp():
"""Return the id of the current process group.
:rtype: int
"""
return 0
def getpid():
"""Return the current process id.
:rtype: int
"""
return 0
def getppid():
"""Return the parent's process id.
:rtype: int
"""
return 0
def getuid():
"""Return the current process's user id.
:rtype: int
"""
return 0
def getenv(varname, value=None):
"""Return the value of the environment variable varname if it exists, or
value if it doesn't.
:type varname: string
:type value: T
:rtype: string | T
"""
pass
def putenv(varname, value):
"""Set the environment variable named varname to the string value.
:type varname: string
:rtype: None
"""
pass
def setegid(egid):
"""Set the current process's effective group id.
:type egid: int
:rtype: None
"""
pass
def seteuid(euid):
"""Set the current process's effective user id.
:type euid: int
:rtype: None
"""
pass
def setgid(gid):
"""Set the current process' group id.
:type gid: int
:rtype: None
"""
pass
def setgroups(groups):
"""Set the list of supplemental group ids associated with the current
process to groups.
:type groups: collections.Iterable[int]
:rtype: None
"""
pass
def setpgid(pid, pgrp):
"""Call the system call setpgid() to set the process group id of the
process with id pid to the process group with id pgrp.
:type pid: int
:type pgrp: int
:rtype: None
"""
pass
def setregid(rgid, egid):
"""Set the current process's real and effective group ids.
:type rgid: int
:type egid: int
:rtype: None
"""
pass
def setreuid(ruid, euid):
"""Set the current process's real and effective user ids.
:type ruid: int
:type euid: int
:rtype None
"""
pass
def setsid():
"""Call the system call getsid().
:rtype: None
"""
pass
def setuid(uid):
"""Set the current process's user id.
:type uid: int
:rtype: None
"""
pass
def strerror(code):
"""Return the error message corresponding to the error code in code.
:type code: int
:rtype: string
"""
return ''
def umask(mask):
"""Set the current numeric umask and return the previous umask.
:type mask: int
:rtype: int
"""
return 0
def uname():
"""Return a 5-tuple containing information identifying the current
operating system.
:rtype: (string, string, string, string, string)
"""
return '', '', '', '', ''
def unsetenv(varname):
"""Unset (delete) the environment variable named varname.
:type varname: string
:rtype: None
"""
pass
def fdopen(fd, mode='r', bufsize=-1):
"""Return an open file object connected to the file descriptor fd.
:type fd: int
:type mode: string
:type bufsize: int
:rtype: file
"""
return file()
def popen(command, mode='r', bufsize=-1):
"""Open a pipe to or from command.
:type command: string
:type mode: string
:type bufsize: int
:rtype: io.FileIO[bytes]
"""
pass
def tmpfile():
"""Return a new file object opened in update mode (w+b).
:rtype: io.FileIO[bytes]
"""
pass
def popen2(cmd, mode='r', bufsize=-1):
"""Execute cmd as a sub-process and return the file objects (child_stdin,
child_stdout).
:type cmd: string
:type mode: string
:type bufsize: int
:rtype: (io.FileIO[bytes], io.FileIO[bytes])
"""
pass
def popen3(cmd, mode='r', bufsize=-1):
"""Execute cmd as a sub-process and return the file objects (child_stdin,
child_stdout, child_stderr).
:type cmd: string
:type mode: string
:type bufsize: int
:rtype: (io.FileIO[bytes], io.FileIO[bytes], io.FileIO[bytes])
"""
pass
def popen4(cmd, mode='r', bufsize=-1):
"""Execute cmd as a sub-process and return the file objects (child_stdin,
child_stdout_and_stderr).
:type cmd: string
:type mode: string
:type bufsize: int
:rtype: (io.FileIO[bytes], io.FileIO[bytes])
"""
pass
def close(fd):
"""Close file descriptor fd.
:type fd: int
:rtype: None
"""
pass
def dup(fd):
"""Return a duplicate of file descriptor fd.
:type fd: int
:rtype: int
"""
return 0
def dup2(fd, fd2):
"""Duplicate file descriptor fd to fd2, closing the latter first if
necessary.
:type fd: int
:type fd2: int
:rtype: None
"""
pass
def fchown(fd, uid, gid):
"""Change the owner and group id of the file given by fd to the numeric
uid and gid.
:type fd: int
:type uid: int
:type gid: int
:rtype: None
"""
pass
def fdatasync(fd):
"""Force write of file with filedescriptor fd to disk.
:type fd: int
:rtype: None
"""
pass
def fpathconf(fd, name):
"""Return system configuration information relevant to an open file.
:type fd: int
:type name: string | int
"""
pass
def fstat(fd):
"""Return status for file descriptor fd, like stat().
:type fd: int
:rtype: os.stat_result
"""
pass
def fstatvfs(fd):
"""Return information about the filesystem containing the file associated
with file descriptor fd, like statvfs().
:type fd: int
:rtype: os.statvfs_result
"""
pass
def fsync(fd):
"""Force write of file with filedescriptor fd to disk.
:type fd: int
:rtype: None
"""
pass
def ftruncate(fd, length):
"""Truncate the file corresponding to file descriptor fd, so that it is at
most length bytes in size.
:type fd: int
:type length: numbers.Integral
:rtype: None
"""
pass
def isatty(fd):
"""Return True if the file descriptor fd is open and connected to a
tty(-like) device, else False.
:type fd: int
:rtype: bool
"""
return False
def lseek(fd, pos, how):
"""Set the current position of file descriptor fd to position pos, modified
by how.
:type fd: int
:type pos: numbers.Integral
:type how: int
:rtype: None
"""
pass
def open(file, flags, mode=0o777):
"""Open the file file and set various flags according to flags and possibly
its mode according to mode.
:type file: string
:type flags: int
:type mode: int
:rtype: int
"""
return 0
def openpty():
"""Open a new pseudo-terminal pair.
:rtype: (int, int)
"""
return 0, 0
def pipe():
"""Create a pipe.
:rtype: (int, int)
"""
return 0, 0
def read(fd, n):
"""Read at most n bytes from file descriptor fd.
:type fd: int
:type n: numbers.Integral
:rtype: bytes
"""
pass
def tcgetpgrp(fd):
"""Return the process group associated with the terminal given by fd.
:type fd: int
:rtype: int
"""
return 0
def tcsetpgrp(fd, pg):
"""Set the process group associated with the terminal given by fd to pg.
:type fd: int
:type pg: int
:rtype: None
"""
pass
def ttyname(fd):
"""Return a string which specifies the terminal device associated with file
descriptor fd.
:type fd: int
:rtype: string
"""
return ''
def write(fd, str):
"""Write the string str to file descriptor fd. Return the number of bytes
actually written.
:type fd: int
:type str: bytes
:rtype: int
"""
return 0
def access(path, mode):
"""Use the real uid/gid to test for access to path.
:type path: bytes | unicode
:type mode: int
:rtype: bool
"""
return False
def chdir(path):
"""Change the current working directory to path.
:type path: bytes | unicode
:rtype: None
"""
pass
def fchdir(fd):
"""Change the current working directory to the directory represented by the
file descriptor fd.
:type fd: int
:rtype: None
"""
pass
def getcwd():
"""Return a string representing the current working directory.
:rtype: string
"""
return ''
def chflags(path, flags):
"""Set the flags of path to the numeric flags.
:type path: bytes | unicode
:type flags: int
:rtype: None
"""
pass
def chroot(path):
"""Change the root directory of the current process to path.
:type path: bytes | unicode
:rtype: None
"""
pass
def chmod(path, mode):
"""Change the mode of path to the numeric mode.
:type path: bytes | unicode
:type mode: int
:rtype: None
"""
pass
def chown(path, uid, gid):
"""Change the owner and group id of path to the numeric uid and gid.
:type path: bytes | unicode
:type uid: int
:type gid: int
:rtype: None
"""
pass
def lchflags(path, flags):
"""Set the flags of path to the numeric flags, like chflags(), but do not
follow symbolic links.
:type path: bytes | unicode
:type flags: int
:rtype: None
"""
pass
def lchmod(path, mode):
"""Change the mode of path to the numeric mode. If path is a symlink, this
affects the symlink rather than the target.
:type path: bytes | unicode
:type mode: int
:rtype: None
"""
pass
def lchown(path, uid, gid):
"""Change the owner and group id of path to the numeric uid and gid. This
function will not follow symbolic links.
:type path: bytes | unicode
:type uid: int
:type gid: int
:rtype: None
"""
pass
def link(source, link_name):
"""Create a hard link pointing to source named link_name.
:type source: bytes | unicode
:type link_name: bytes | unicode
:rtype: None
"""
pass
def listdir(path):
"""Return a list containing the names of the entries in the directory given
by path.
:type path: T <= bytes | unicode
:rtype: list[T]
"""
return []
def lstat(path):
"""Perform the equivalent of an lstat() system call on the given path.
Similar to stat(), but does not follow symbolic links.
:type path: bytes | unicode
:rtype: os.stat_result
"""
pass
def mkfifo(path, mode=0o666):
"""Create a FIFO (a named pipe) named path with numeric mode mode.
:type path: bytes | unicode
:type mode: int
:rtype: None
"""
pass
def mknod(filename, mode=0o600, device=0):
"""Create a filesystem node (file, device special file or named pipe) named
filename.
:type filename: bytes | unicode
:type mode: int
:type device: int
:rtype: None
"""
pass
def major(device):
"""Extract the device major number from a raw device number (usually the
st_dev or st_rdev field from stat).
:type device: int
:rtype: int
"""
return 0
def minor(device):
"""Extract the device minor number from a raw device number (usually the
st_dev or st_rdev field from stat).
:type device: int
:rtype: int
"""
return 0
def makedev(major, minor):
"""Compose a raw device number from the major and minor device numbers.
:type major: int
:type minor: int
:rtype: int
"""
return 0
def mkdir(path, mode=0o777):
"""Create a directory named path with numeric mode mode.
:type path: bytes | unicode
:type mode: int
:rtype: None
"""
pass
def makedirs(path, mode=0o777, exist_ok=False):
"""Recursive directory creation function.
:type path: bytes | unicode
:type mode: int
:type exist_ok: int
:rtype: None
"""
pass
def pathconf(path, name):
"""Return system configuration information relevant to a named file.
:type path: bytes | unicode
:type name: int | string
"""
pass
def readlink(path):
"""Return a string representing the path to which the symbolic link points.
:type path: T <= bytes | unicode
:rtype: T
"""
return path
def remove(path):
"""Remove (delete) the file path.
:type path: bytes | unicode
:rtype: None
"""
pass
def removedirs(path):
"""Remove directories recursively.
:type path: bytes | unicode
:rtype: None
"""
pass
def rename(src, dst):
"""Rename the file or directory src to dst.
:type src: bytes | unicode
:type dst: bytes | unicode
:rtype: None
"""
pass
def renames(old, new):
"""Recursive directory or file renaming function.
:type old: bytes | unicode
:type new: bytes | unicode
:rtype: None
"""
pass
def rmdir(path):
"""Remove (delete) the directory path.
:type path: bytes | unicode
:rtype: None
"""
pass
def stat(path, dir_fd=None, follow_symlinks=True):
"""Perform the equivalent of a stat() system call on the given path.
:type path: bytes | unicode | int
:type dir_fd: int | None
:type follow_symlinks: bool | None
:rtype: os.stat_result
"""
pass
def stat_float_times(newvalue=None):
"""Determine whether stat_result represents time stamps as float objects.
:type newvalue: bool | None
:rtype: bool
"""
return False
def statvfs(path):
"""Perform a statvfs() system call on the given path.
:type path: bytes | unicode
:rtype: os.statvfs_result
"""
pass
def symlink(source, link_name, target_is_directory=False, dir_fd=None):
"""Create a symbolic link pointing to source named link_name.
:type source: bytes | unicode
:type link_name: bytes| unicode
:type target_is_directory: bool
:type dir_fd: int | None
:rtype: None
"""
pass
def tempnam(dir=None, prefix=None):
"""Return a unique path name that is reasonable for creating a temporary
file.
:type dir: bytes | unicode
:type prefix: bytes | unicode
:rtype: string
"""
return ''
def tmpnam():
"""Return a unique path name that is reasonable for creating a temporary
file.
:rtype: string
"""
return ''
def unlink(path):
"""Remove (delete) the file path.
:type path: bytes | unicode
:rtype: None
"""
pass
def utime(path, times):
"""Set the access and modified times of the file specified by path.
:type path: bytes | unicode
:type times: (numbers.Real, numbers.Real) | None
:rtype: None
"""
pass
def walk(top, topdown=True, onerror=None, followlinks=False):
"""Generate the file names in a directory tree by walking the tree either
top-down or bottom-up.
:type top: T <= bytes | unicode
:type topdown: bool
:type onerror: ((Exception) -> None) | None
:rtype: collections.Iterator[(T, list[T], list[T])]
"""
return []
def execl(path, *args):
"""Execute a new program, replacing the current process.
:type path: bytes | unicode
:rtype: None
"""
pass
def execle(path, *args):
"""Execute a new program, replacing the current process.
:type path: bytes | unicode
:rtype: None
"""
pass
def execlp(file, *args):
"""Execute a new program, replacing the current process.
:type file: bytes | unicode
:rtype: None
"""
pass
def execlpe(file, *args):
"""Execute a new program, replacing the current process.
:type file: bytes | unicode
:rtype: None
"""
pass
def execv(path, args):
"""Execute a new program, replacing the current process.
:type path: bytes | unicode
:type args: collections.Iterable
:rtype: None
"""
pass
def execve(path, args, env):
"""Execute a new program, replacing the current process.
:type path: bytes | unicode
:type args: collections.Iterable
:type env: collections.Mapping
:rtype: None
"""
pass
def execvp(file, args):
"""Execute a new program, replacing the current process.
:type file: bytes | unicode
:type args: collections.Iterable
:rtype: None
"""
pass
def execvpe(file, args, env):
"""Execute a new program, replacing the current process.
:type file: bytes | unicode
:type args: collections.Iterable
:type env: collections.Mapping
:rtype: None
"""
pass
def _exit(n):
"""Exit the process with status n, without calling cleanup handlers,
flushing stdio buffers, etc.
:type n: int
:rtype: None
"""
pass
def fork():
"""Fork a child process.
:rtype: int
"""
return 0
def forkpty():
"""Fork a child process, using a new pseudo-terminal as the child's
controlling terminal.
:rtype: (int, int)
"""
return 0, 0
def kill(pid, sig):
"""Send signal sig to the process pid.
:type pid: int
:type sig: int
:rtype: None
"""
pass
def killpg(pgid, sig):
"""Send the signal sig to the process group pgid.
:type pgid: int
:type sig: int
:rtype: None
"""
pass
def nice(increment):
"""Add increment to the process's "niceness".
:type increment: int
:rtype: int
"""
return 0
def plock(op):
"""Lock program segments into memory.
:rtype: None
"""
pass
def spawnl(mode, path, *args):
"""Execute the program path in a new process.
:type mode: int
:type path: bytes | unicode
:rtype: int
"""
return 0
def spawnle(mode, path, *args):
"""Execute the program path in a new process.
:type mode: int
:type path: bytes | unicode
:rtype: int
"""
return 0
def spawnlp(mode, file, *args):
"""Execute the program path in a new process.
:type mode: int
:type file: bytes | unicode
:rtype: int
"""
return 0
def spawnlpe(mode, file, *args):
"""Execute the program path in a new process.
:type mode: int
:type file: bytes | unicode
:rtype: int
"""
return 0
def spawnv(mode, path, args):
"""Execute the program path in a new process.
:type mode: int
:type path: bytes | unicode
:type args: collections.Iterable
:rtype: int
"""
return 0
def spawnve(mode, path, args, env):
"""Execute the program path in a new process.
:type mode: int
:type path: bytes | unicode
:type args: collections.Iterable
:type env: collections.Mapping
:rtype: int
"""
return 0
def spawnvp(mode, file, args):
"""Execute the program path in a new process.
:type mode: int
:type file: bytes | unicode
:type args: collections.Iterable
:rtype: int
"""
return 0
def spawnvpe(mode, file, args, env):
"""Execute the program path in a new process.
:type mode: int
:type file: bytes | unicode
:type args: collections.Iterable
:type env: collections.Mapping
:rtype: int
"""
return 0
def system(command):
"""Execute the command (a string) in a subshell.
:type command: bytes | unicode
:rtype: int
"""
return 0
def times():
"""Return a 5-tuple of floating point numbers indicating accumulated
(processor or other) times, in seconds.
:rtype: (float, float, float, float, float)
"""
return 0.0, 0.0, 0.0, 0.0, 0.0
def wait():
"""Wait for completion of a child process, and return a tuple containing
its pid and exit status indication
:rtype: (int, int)
"""
return 0, 0
def waitpid(pid, options):
"""Wait for completion of a child process given by process id pid, and
return a tuple containing its process id and exit status indication.
:type pid: int
:type options: int
:rtype: (int, int)
"""
return 0, 0
def wait3(options):
"""Similar to waitpid(), except no process id argument is given and a
3-element tuple containing the child's process id, exit status indication,
and resource usage information is returned.
:type options: int
:rtype: (int, int, resource.struct_rusage)
"""
pass
def wait4(pid, options):
"""Similar to waitpid(), except a 3-element tuple, containing the child's
process id, exit status indication, and resource usage information is
returned.
:type pid: int
:type options: int
:rtype: (int, int, resource.struct_rusage)
"""
pass
def urandom(n):
"""Return a string of n random bytes suitable for cryptographic use.
:type n: int
:rtype: bytes
"""
return b''
剩下的就是对这些api的练习了。
__author__ = 'Zechary'
#coding=utf-8
import os
#print os.getgid()
#print os.getenv('PATH')
fd = os.open('abc.txt', os.O_RDWR)
fc = os.fdopen(fd, "w+")
print 'file size %d' % fc.tell()
fc.write("learn os module ")
print 'file size %d' % fc.tell()
os.lseek(fd, 0, 0)
str = os.read(fd, 100)
print 'Read string is :', str
ret = os.dup(fd)
print 'dup ret: %d' % ret
info = os.fstat(fd)
print 'info: %d %d' % (info.st_uid, info.st_mode)
str = os.getcwd()
print 'cwd is :', str
fc.close()