当cp没有时,为什么shutil.copy()会引发权限异常？

Question

shutil.copy()引发了权限错误:

Traceback (most recent call last):
  File "copy-test.py", line 3, in <module>
    shutil.copy('src/images/ajax-loader-000000-e3e3e3.gif', 'bin/styles/blacktie/images')
  File "/usr/lib/python2.7/shutil.py", line 118, in copy
    copymode(src, dst)
  File "/usr/lib/python2.7/shutil.py", line 91, in copymode
    os.chmod(dst, mode)
OSError: [Errno 1] Operation not permitted: 'bin/styles/blacktie/images/ajax-loader-000000-e3e3e3.gif'

copy-test.py:

import shutil

shutil.copy('src/images/ajax-loader-000000-e3e3e3.gif', 'bin/styles/blacktie/images')

我从命令行运行copy-test.py:

python copy-test.py

但是cp从同一文件的命令行运行到同一目标不会导致错误.为什么？

Answer 1

失败的操作chmod不是复制本身:

  File "/usr/lib/python2.7/shutil.py", line 91, in copymode
    os.chmod(dst, mode)
OSError: [Errno 1] Operation not permitted: 'bin/styles/blacktie/images/ajax-loader-000000-e3e3e3.gif'

这表示该文件已存在并由另一个用户拥有.

shutil.copy指定复制权限位.如果您只想复制文件内容,请使用shutil.copyfile(src, dst),或者shutil.copyfile(src, os.path.join(dst, os.path.basename(src)))如果dst是目录.

一个与dst文件或目录一起使用的函数,不会复制权限位:

def copy(src, dst):
    if os.path.isdir(dst):
        dst = os.path.join(dst, os.path.basename(src))
    shutil.copyfile(src, dst)