首页 文章

如何在Python中更改目录(cd)?

提问于
浏览 1338
542

cd 如在shell命令中更改工作目录 .

如何在Python中更改当前工作目录?

14 回答

  • 590

    以下是更改工作目录的上下文管理器示例 . 它比其他地方提到的更为简单,但这可以完成工作 .

    上下文管理器:cd

    import os
    
    class cd:
        """Context manager for changing the current working directory"""
        def __init__(self, newPath):
            self.newPath = os.path.expanduser(newPath)
    
        def __enter__(self):
            self.savedPath = os.getcwd()
            os.chdir(self.newPath)
    
        def __exit__(self, etype, value, traceback):
            os.chdir(self.savedPath)
    

    或者使用ContextManager尝试more concise equivalent(below) .

    示例

    import subprocess # just to call an arbitrary command e.g. 'ls'
    
    # enter the directory like this:
    with cd("~/Library"):
       # we are in ~/Library
       subprocess.call("ls")
    
    # outside the context manager we are back wherever we started.
    
  • 263

    您可以使用以下命令更改工作目录:

    import os
    
    os.chdir(path)
    

    使用此方法时,有两个最佳做法:

    • 在无效路径上捕获异常(WindowsError,OSError) . 如果抛出异常,请不要执行任何递归操作,尤其是破坏性操作 . 它们将在旧路上运行而不是新路径 .

    • 完成后返回旧目录 . 这可以通过将chdir调用包装在上下文管理器中以异常安全的方式完成,就像Brian M. Hunt在_762518中所做的那样 .

    更改子进程中的当前工作目录不会更改父进程中的当前工作目录 . 对于Python解释器也是如此 . 您不能使用 os.chdir() 来更改调用进程的CWD .

  • 128

    正如其他人已经指出的那样,上述所有解决方案只会改变当前进程的工作目录 . 当您退回到Unix shell时,这会丢失 . 如果绝望你 can 用这个可怕的黑客改变Unix上的父shell目录:

    def quote_against_shell_expansion(s):
        import pipes
        return pipes.quote(s)
    
    def put_text_back_into_terminal_input_buffer(text):
        # use of this means that it only works in an interactive session
        # (and if the user types while it runs they could insert characters between the characters in 'text'!)
        import fcntl, termios
        for c in text:
            fcntl.ioctl(1, termios.TIOCSTI, c)
    
    def change_parent_process_directory(dest):
        # the horror
        put_text_back_into_terminal_input_buffer("cd "+quote_against_shell_expansion(dest)+"\n")
    
  • 87

    os.chdir() 是正确的方法 .

  • 22

    进一步指向Brian指出的方向并基于sh(1.0.8)

    from sh import cd, ls
    
    cd('/tmp')
    print ls()
    
  • 11

    如果您使用的是相对较新版本的Python,您还可以使用上下文管理器,例如this one

    from __future__ import with_statement
    from grizzled.os import working_directory
    
    with working_directory(path_to_directory):
        # code in here occurs within the directory
    
    # code here is in the original directory
    

    UPDATE

    如果你喜欢自己动手:

    import os
    from contextlib import contextmanager
    
    @contextmanager
    def working_directory(directory):
        owd = os.getcwd()
        try:
            os.chdir(directory)
            yield directory
        finally:
            os.chdir(owd)
    
  • 11
    #import package
    import os
    
    #change directory
    os.chdir('my_path')
    
    #get location 
    os.getcwd()
    

    此外,最好在OS包中检查所有其他有用的命令https://docs.python.org/3/library/os.html

  • 11

    为了便于交互使用,ipython内置了所有常见的shell命令 .

  • 6

    如果您想执行类似“cd ..”选项的操作,只需键入:

    os.chdir("..")

    它与Windows cmd中相同:cd ..当然 import os 是必要的(例如将其键入代码的第1行)

  • 4
    import os
    
    abs_path = 'C://a/b/c'
    rel_path = './folder'
    
    os.chdir(abs_path)
    os.chdir(rel_path)
    

    您可以将它们与os.chdir(abs_path)或os.chdir(rel_path)一起使用,不需要调用os.getcwd()来使用相对路径 .

  • 1

    我会像这样使用 os.chdir

    os.chdir("/path/to/change/to")
    

    顺便说一下,如果你需要弄清楚你当前的路径,请使用 os.getcwd() .

    更多here

  • 1

    更改脚本进程的当前目录是微不足道的 . 我认为问题实际上是如何更改调用python脚本的命令窗口的当前目录,这是非常困难的 . Windows中的Bat脚本或Bash shell中的Bash脚本可以使用普通的cd命令执行此操作,因为shell本身就是解释器 . 在Windows和Linux中,Python是一个程序,没有程序可以直接更改其父级环境 . 然而,简单的shell脚本与执行大多数硬件的Python脚本的组合可以实现期望的结果 . 例如,要创建带有遍历/转发/选择重访的遍历历史的扩展cd命令,我编写了一个由简单的bat脚本调用的相对复杂的Python脚本 . 遍历列表存储在文件中,目标目录位于第一行 . 当python脚本返回时,bat脚本读取文件的第一行并使其成为cd的参数 . 完整的bat脚本(减去评论简洁)是:

    if _%1 == _. goto cdDone
    if _%1 == _? goto help
    if /i _%1 NEQ _-H goto doCd
    :help
    echo d.bat and dSup.py 2016.03.05. Extended chdir.
    echo -C = clear traversal list.
    echo -B or nothing = backward (to previous dir).
    echo -F or - = forward (to next dir).
    echo -R = remove current from list and return to previous.
    echo -S = select from list.
    echo -H, -h, ? = help.
    echo . = make window title current directory.
    echo Anything else = target directory.
    goto done
    
    :doCd
    %~dp0dSup.py %1
    for /F %%d in ( %~dp0dSupList ) do (
        cd %%d
        if errorlevel 1 ( %~dp0dSup.py -R )
        goto cdDone
    )
    :cdDone
    title %CD%
    :done
    

    python脚本dSup.py是:

    import sys, os, msvcrt
    
    def indexNoCase ( slist, s ) :
        for idx in range( len( slist )) :
            if slist[idx].upper() == s.upper() :
                return idx
        raise ValueError
    
    # .........main process ...................
    if len( sys.argv ) < 2 :
        cmd = 1 # No argument defaults to -B, the most common operation
    elif sys.argv[1][0] == '-':
        if len(sys.argv[1]) == 1 :
            cmd = 2 # '-' alone defaults to -F, second most common operation.
        else :
            cmd = 'CBFRS'.find( sys.argv[1][1:2].upper())
    else :
        cmd = -1
        dir = os.path.abspath( sys.argv[1] ) + '\n'
    
    # cmd is -1 = path, 0 = C, 1 = B, 2 = F, 3 = R, 4 = S
    
    fo = open( os.path.dirname( sys.argv[0] ) + '\\dSupList', mode = 'a+t' )
    fo.seek( 0 )
    dlist = fo.readlines( -1 )
    if len( dlist ) == 0 :
        dlist.append( os.getcwd() + '\n' ) # Prime new directory list with current.
    
    if cmd == 1 : # B: move backward, i.e. to previous
        target = dlist.pop(0)
        dlist.append( target )
    elif cmd == 2 : # F: move forward, i.e. to next
        target = dlist.pop( len( dlist ) - 1 )
        dlist.insert( 0, target )
    elif cmd == 3 : # R: remove current from list. This forces cd to previous, a
                    # desireable side-effect
        dlist.pop( 0 )
    elif cmd == 4 : # S: select from list
    # The current directory (dlist[0]) is included essentially as ESC.
        for idx in range( len( dlist )) :
            print( '(' + str( idx ) + ')', dlist[ idx ][:-1])
        while True :
            inp = msvcrt.getche()
            if inp.isdigit() :
                inp = int( inp )
                if inp < len( dlist ) :
                    print( '' ) # Print the newline we didn't get from getche.
                    break
            print( ' is out of range' )
    # Select 0 means the current directory and the list is not changed. Otherwise
    # the selected directory is moved to the top of the list. This can be done by
    # either rotating the whole list until the selection is at the head or pop it
    # and insert it to 0. It isn't obvious which would be better for the user but
    # since pop-insert is simpler, it is used.
        if inp > 0 :
            dlist.insert( 0, dlist.pop( inp ))
    
    elif cmd == -1 : # -1: dir is the requested new directory.
    # If it is already in the list then remove it before inserting it at the head.
    # This takes care of both the common case of it having been recently visited
    # and the less common case of user mistakenly requesting current, in which
    # case it is already at the head. Deleting and putting it back is a trivial
    # inefficiency.
        try:
            dlist.pop( indexNoCase( dlist, dir ))
        except ValueError :
            pass
        dlist = dlist[:9] # Control list length by removing older dirs (should be
                          # no more than one).
        dlist.insert( 0, dir ) 
    
    fo.truncate( 0 )
    if cmd != 0 : # C: clear the list
        fo.writelines( dlist )
    
    fo.close()
    exit(0)
    
  • 0

    使用生成器和装饰器很容易编写 cd() .

    from contextlib import contextmanager
    import os
    
    @contextmanager
    def cd(newdir):
        prevdir = os.getcwd()
        os.chdir(os.path.expanduser(newdir))
        try:
            yield
        finally:
            os.chdir(prevdir)
    

    然后,即使抛出异常,该目录也会被还原:

    os.chdir('/home')
    
    with cd('/tmp'):
        # ...
        raise Exception("There's no place like home.")
    # Directory is now back to '/home'.
    
  • -5

    os.chdir()cd 的Pythonic版本 .

相关问题