cd
是改变工作目录的shell命令。
如何更改 Python 中的当前工作目录?
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,需要遵循两个最佳实践:
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。Python 解释器也是如此。您不能用于os.chdir()
更改调用进程的 CWD。
这是更改工作目录的上下文管理器的示例。它比其他地方提到的ActiveState 版本更简单,但这可以完成工作。
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尝试更简洁的等价物(如下)。
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.
cd()
使用生成器和装饰器很容易编写。
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,即使在引发异常后,目录也会恢复:
os.chdir('/home')
with cd('/tmp'):
# ...
raise Exception("There's no place like /home.")
# Directory is now back to '/home'.
如果您使用的是相对较新的 Python 版本,您还可以使用上下文管理器,例如这个:
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
更新
如果您更喜欢自己动手:
import os
from contextlib import contextmanager
@contextmanager
def working_directory(directory):
owd = os.getcwd()
try:
os.chdir(directory)
yield directory
finally:
os.chdir(owd)
正如其他人已经指出的那样,上述所有解决方案仅更改当前进程的工作目录。当您退出到 Unix shell 时,这将丢失。如果绝望,你可以用这个可怕的 hack 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")
os.chdir()
是 Pythonic 版本的cd
.
os.chdir()
是正确的方法。
import os
abs_path = 'C://a/b/c'
rel_path = './folder'
os.chdir(abs_path)
os.chdir(rel_path)
您可以同时使用 os.chdir(abs_path) 或 os.chdir(rel_path),无需调用 os.getcwd() 来使用相对路径。
进一步进入 Brian 指出的方向并基于sh (1.0.8+)
from sh import cd, ls
cd('/tmp')
print ls()
如果您想执行类似“cd..”选项的操作,只需键入:
os.chdir("..")
它与 Windows cmd 中的相同: cd.. 当然import os是必需的(例如,将其键入为代码的第一行)
路径库中的Path
对象为此提供了上下文管理器和方法:chdir
from path import Path
with Path("somewhere"):
...
Path("somewhere").chdir()
如果您使用 spyder 和 love GUI,您只需单击屏幕右上角的文件夹按钮并浏览您想要作为当前目录的文件夹/目录。这样做之后,您可以转到 spyder IDE 窗口的文件资源管理器选项卡,您可以看到那里存在的所有文件/文件夹。要检查您当前的工作目录,请转到 spyder IDE 的控制台并简单地键入
pwd
它将打印与您之前选择的相同路径。
更改脚本进程的当前目录很简单。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,这非常困难。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 都是一个程序,没有任何程序可以直接改变其父环境。然而,将一个简单的 shell 脚本与一个 Python 脚本相结合,可以完成大多数困难的工作,可以达到预期的效果。例如,为了制作一个带有遍历历史的扩展 cd 命令,用于向后/向前/选择重新访问,我编写了一个相对复杂的 Python 脚本,由一个简单的 bat 脚本调用。遍历列表存储在一个文件中,目标目录在第一行。当 python 脚本返回时,bat 脚本读取文件的第一行并将其作为 cd 的参数。完整的 bat 脚本(为简洁起见减去注释)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)