Python删除文件-“当前正被另一个进程使用”

Question

要求

我必须尝试创建一个程序来删除所有损坏的图像（以及小于 400x400 的图像）并将其余图像过滤成 10,000 个组。

问题

目前，当我尝试删除任何“损坏”的图像时，它表示该文件当前正在被另一个进程使用，每个错误如下：

该进程无法访问该文件，因为它正被另一个进程使用。

采取的步骤

我尝试了多种方法来释放文件，包括使用“后退踏板”策略，应用程序移动到下一个图像，然后后退踏板尝试删除该图像，但它仍然保持打开状态。 如果我在 Python 打开时尝试手动删除图像，它会很高兴地通过。

请看下面的代码：

---

def confirmIt():
#======== Confirm Selection and Move files to new sub-directory:
if not folderPath.get() == "":                          ## make sure not blank
    source = folderPath.get()                           ## set source path 
    size = 0
    broken = False

    for fname in os.listdir(source):
        if  fname.lower().endswith(extensions):
            imageName = source+"\\"+fname               ## set the source location of the image
            try: 
                img = Image.open(imageName)
                width, height = img.size                    ## get the dimensions
                size = width * height / 1000
                broken = False
                img.close()
            except IOError, e:
                broken = True
                img.close()

            if ( broken == True ):
                def handleRemoveReadonly(func, path, exc):
                    excvalue = exc[1]
                    if func in (os.rmdir, os.remove) and excvalue.errno == errno.EACCES:
                        os.chmod(path, stat.S_IRWXU| stat.S_IRWXG| stat.S_IRWXO)
                        func(path)
                    else:
                        raise
                try:
                    os.remove(imageName)                ## Remove all remaining images that don't match the preset requirements (<400 and is an image)

额外信息

请注意，我也在使用 GUI，因此“resultMessage”和类似的输出/输入字段就是出于这个原因。

---

编辑：

在与@Cyphase 反复讨论后，我确定了问题所在。下降的帖子是由于我为他编辑了带有回溯的 OP。我并不真正使用这个论坛，因为我通常不需要编码。此应用程序的更多主题可能会出现。谢谢。

---

Answer 1

您的问题是您正在修改底层文件系统（通过删除图像），然后遍历（旧）文件列表。

这就是您的循环尝试打开不再存在的图像的原因。

解决方法是先存储文件列表，然后循环遍历文件列表；而不是os.listdir() 的输出（将被缓存）。

您还应该排除代码的一些组成部分。试试这个版本：

from itertools import izip_longest

# https://docs.python.org/2/library/itertools.html
def grouper(iterable, n, fillvalue=None):
    "Collect data into fixed-length chunks or blocks"
    # grouper('ABCDEFG', 3, 'x') --> ABC DEF Gxx
    args = [iter(iterable)] * n
    return izip_longest(fillvalue=fillvalue, *args)

def get_valid_images(image_path):
    extensions = ['*.jpg']
    return [f for f in os.listdir(image_path)
            if f.lower().endswith(extensions)]

def is_valid_image(image_path):
    try:
        img = Image.open(image_path)
        img.load()
        width, height = img.size
        img.close()
        return True
     except IOError as e:
        print(e)
        img.close()
        return None
     finally:
        img.close()
    return None

def confirmIt():
    # Confirm selection and move files to new sub-directory
    source = folderPath.get()  # set source path
    if not source:
        return False # If there is no source no point going
                     # head
    file_list = get_valid_images(source)
    valid_images = []
    for fname in file_list:
        image_dim = is_valid_image(os.path.join(source, fname))
        if image_dim:
            valid_images.append(source)

    # Now, group the resulting list in bunches for your move
    for dir_num, filenames in enumerate(grouper(valid_images, 5)):
        dest = os.path.join(source, str(dir_num))
        if not os.path.exists(dest):
            try:
                os.makedirs(dest)
            except OSError, e:
                print(e)
                continue # Skip this set, as we cannot make the dir
        for fname in filenames:
            shutil.move(fname, dest)
            print('Moving {}'.format(fname))

Answer 2

经过多次反复，这段代码应该可以做你想做的事，除非有任何错误:)。给其他任何人；可能还会进行一些更改以消除任何问题。

from __future__ import print_function

import errno
import os

try:
    from itertools import zip_longest  # Python 3
except ImportError:  # Python 2
    from itertools import izip_longest as zip_longest  # Python 2

from PIL import Image

DEFAULT_IMAGE_EXTS = ('.jpg',)


# From the recipes section of the itertools documentation:
# https://docs.python.org/3/library/itertools.html#itertools-recipes
def grouper(iterable, n, fillvalue=None):
    "Collect data into fixed-length chunks or blocks"
    # grouper('ABCDEFG', 3, 'x') --> ABC DEF Gxx"
    args = [iter(iterable)] * n
    return zip_longest(*args, fillvalue=fillvalue)


def makedirs(d):
    try:
        os.makedirs(d)
    except OSError as e:
        # If the file already exists, and is a directory
        if e.errno == errno.EEXIST and os.path.isdir(d):
            created = False
        # It's some other error, or the existing file is not a directory
        else:
            raise
    else:
        created = True

    return created


def get_valid_filenames(directory, extensions):
    for filename in os.listdir(directory):
        if filename.lower().endswith(extensions):
            yield filename


def get_corrupt_image_filenames(directory, extensions=DEFAULT_IMAGE_EXTS):
    for filename in get_valid_filenames(directory, extensions):
        image_path = os.path.join(directory, filename)
        try:
            with open(image_path, 'rb') as filehandle:
                Image.open(filehandle)
                # img = Image.open(filehandle)
                # img.load()  # I don't think this is needed, unless
                #               the corruption is not in the header.
        except IOError:
            yield filename


def confirm_it(directory, extensions, images_per_dir=5000):
    # Confirm selection and move files to new sub-directory
    if directory:
        for corrupt_file_name in get_corrupt_image_filenames(directory):
            os.remove(os.path.join(directory, corrupt_file_name))

        valid_images = get_valid_filenames(directory, extensions)
        grouped_image_file_names = grouper(valid_images, images_per_dir)
        for subdir, image_filenames in enumerate(grouped_image_file_names):
            for filename in image_filenames:
                from_path = os.path.join(directory, filename)
                to_dir = os.path.join(directory, str(subdir))
                to_path = os.path.join(to_dir, filename)

                makedirs(to_dir)

                os.rename(from_path, to_path)


def confirm_it_wrapper():
    confirm_it(directory=folderPath.get(), extensions=extensions)

使用confirm_it_wrapper 代替confirm_it 作为tkinter Button 点击的回调。