I am relatively new to python. I am trying to copy a directory to another directory maintaining the structure.
I am using
shuti开发者_开发技巧l.copytree(src, dst, symlinks=False, ignore=None,
copy_function=copy2, ignore_dangling_symlinks=False)
I am trying to write a call back function for ignore.
My aim is to take a list of files in a list , and copy only those files,ignoring the rest. How do we pass a list into the call back function?
I wrote a simple call back function , but I get some error when I try to run the copyTree function
def abc(src,names):
print(src)
print(names)
Traceback (most recent call last):
File "<pyshell#23>", line 1, in <module>
shutil.copytree('D:\Mytest','D:\PythonTestDest3',symlinks=False,ignore=abc)
File "C:\Python32\lib\shutil.py", line 204, in copytree
if name in ignored_names:
TypeError: argument of type 'NoneType' is not iterable
The return of the ignore function needs to be a list of directories and files to ignore. You aren't returning anything, which returns None
, so you are getting the error TypeError: argument of type 'NoneType' is not iterable
.
Here's an example that will copy the folder structure and the files listed in 'copy_these':
import os.path
copy_these = ['a.txt', 'b.txt', 'c.txt']
def ignore_most(folder, files):
ignore_list = []
for file in files:
full_path = os.path.join(folder, file)
if not os.path.isdir(full_path):
if file not in copy_these:
ignore_list.append(file)
return ignore_list
The shutil module provides a ignore_patterns
function.
This factory function creates a function that can be used as a callable for copytree()‘s ignore argument, ignoring files and directories that match one of the glob-style patterns provided.
The module page shows a couple of examples as well.
The ignore callback function should return a list of names relative to the 'src' directory that should not be copied.
Your example callback returns nothing (ie. None). Then copytree, expecting a list, tries to iterate over it. Since it can't, you get that exception.
If ignore is given, it must be a callable that will receive as its arguments the directory being visited ... and a list of its contents ... The callable must return a sequence of directory and file names relative to the current directory ...; these names will then be ignored in the copy process.
(docs)
My aim is to take a list of files in a list
Try an anonymous function (lambda
) and a list comprehension:
copytree(src, dest,
ignore=lambda d, files: [f for f in files
if f not in files_to_copy
and not is_dir(os.path.join(d, f))])
Note that the lambda
function gets the basenames of the files and directories, not their full paths; kudos @jwhitlock's for the directory handling.
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