chdir
修改当前工作目录到指定目录
Change the current working directory to the specified path.
chmod
修改一个文件的访问权限
Change the access permissions of a file.
chown
把一个目录的属主和属组修改成另一个数字的属主和属组
Change the owner and group id of path to the numeric uid and gid
chroot
修改根目录(在liunx下使用)
Change root directory to path.
ctermid
返回一个进程的控制台的名字
Return the name of the controlling terminal for this process.
getcwd
以字符串格式显示当前工作目录(python解释器的工作目录)
Return a unicode string representing the current working directory.
getegid
获取当前进程的有效组ID
Return the current process's effective group id.
getenv
获取系统的环境变量，环境变量不存在时返回None
Get an environment variable, return None if it doesn't exist.
geteuid
获取当前进程的有效用户ID
Return the current process's effective user id.
getgid
获取当彰进程的组ID
Return the current process's group id.
getgrouplist
返回指定用户的基本组的列表
getgrouplist(user, group) -> list of groups to which a user belongs
Returns a list of groups to which a user belongs.
getgroups
获取一个进程的附加组ID的列表
Return list of supplemental group IDs for the process.
getloadavg
返回当前一个由系统1分钟，5分钟和15分钟的平均负载使用率组成的元组
Return average recent system load information.
Return the number of processes in the system run queue averaged over
the last 1, 5, and 15 minutes as a tuple of three floats.
Raises OSError if the load average was unobtainable.
getlogin
返回当前系统的实际登陆的用户名
Return the actual login name.
getpid
返回当前的进程ID号
Return the current process id.
getppid
返回当前进程的父进程的ID号
Return the parent's process id.
getuid
返回当前进程的用户ID
Return the current process's user id.
kill
结束一个进程
Kill a process with a signal.
killpg
结束掉一个进程组
Kill a process group with a signal.
listdir
返回指定路径下由所有所有文件的名字组成的列表，未指定路径则默认为当前路径
Return a list containing the names of the files in the directory.
path can be specified as either str or bytes. If path is bytes,
the filenames returned will also be bytes; in all other circumstances
the filenames returned will be str.
If path is None, uses the path='.'.
lseek
设置并返回指定文件的指针的位置，
Set the position of a file descriptor. Return the new position.
Return the new cursor position in number of bytes
relative to the beginning of the file.
major
获取一个设备文件的主设备号
Extracts a device major number from a raw device number.
makedev
在系统上创建一个新的设备文件
Composes a raw device number from the major and minor device numbers.
makedirs
递归创建多层目录，如果目标目录已经存在，则报错
Super-mkdir; create a leaf directory and all intermediate ones. Works like
mkdir, except that any intermediate path segment (not just the rightmost)
will be created if it does not exist. If the target directory already
exists, raise an OSError if exist_ok is False. Otherwise no exception is
raised. This is recursive.
minor
获取一个设备文件的次设备号
Extracts a device minor number from a raw device number.
mkdir
创建一个目录
Create a directory.
mkfifo
创建一个管道文件
If dir_fd is not None, it should be a file descriptor open to a directory,
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, using it will raise a NotImplementedError.
nice
为一个进程增加属性，也即修改一个进程的nice值
Add increment to the priority of process and return the new priority.
open
在硬件层面打开文件，返回一个整型的文件描述符
Open a file for low level IO. Returns a file descriptor (integer).
putenv
修改或增加一个环境变量
Change or add an environment variable.
read
读取指定文件的文件描述符，返回字节对象
Read from a file descriptor. Returns a bytes object.
remove
删除指定文件
Remove a file (same as unlink()).
removedirs
删除多层目录，
Super-rmdir; remove a leaf directory and all empty intermediate
ones. Works like rmdir except that, if the leaf directory is
successfully removed, directories corresponding to rightmost path
segments will be pruned away until either the whole path is
consumed or an error occurs. Errors during this latter phase are
ignored -- they generally mean that a directory was not empty.
rename
为一个文件或目录重命名
Rename a file or directory.
rmdir
删除一个目录
Remove a directory.
setegid
设置当前进程的有效组ID
Set the current process's effective group id.
seteuid
设置当前进程的有效用户ID
Set the current process's effective user id.
setgid
设置当前进程的组ID
Set the current process's group id.
setuid
为当前进程设置用户ID
Set the current process's user id.
stat
显示指定路径的详细信息
Perform a stat system call on the given path.
strerror
把错误号码转换成信息字符串
Translate an error code to a message string.
symlink
为指定目录创建软链接
symlink(src, dst, target_is_directory=False, *, dir_fd=None)
Create a symbolic link pointing to src named dst.
sync
强制写入内容到磁盘中
Force write of everything to disk.
system
在子shell中执行系统命令
Execute the command in a subshell.
times
返回系统时间信息的集合
Return a collection containing process timing information.
umask
为文件或目录设置并返回新权限模式
Set the current numeric umask and return the previous umask.
uname
返回当前操作系统的内核信息
Return an object identifying the current operating system.
unlink
删除一个软链接
unlink(path, *, dir_fd=None)
Remove a file (same as remove()).
unsetenv
删除一个环境变量
Delete an environment variable.
utime
为指定路径设置最后访问时间和最后修改时间
utime(path, times=None, *, ns=None, dir_fd=None, follow_symlinks=True)
Set the access and modified time of path.
walk
给定目录名，返回一个由当前目录名，当前目录的子目录以及当前目录下的普通文件组成的元组
Directory tree generator.
For each directory in the directory tree rooted at top (including top
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
the names of the subdirectories in dirpath (excluding '.' and '..').
filenames is a list of the names of the non-directory files in dirpath.
Note that the names in the lists are just names, with no path components.
To get a full path (which begins with top) to a file or directory in
dirpath, do os.path.join(dirpath, name).
