问题 从shutil文件复制线程获取进度

我结合了 Martijn Pieters的回答 有一些进度条形码来自 这个答案 修改工作在PyCharm从 这个答案 这给了我以下。功能 copy_with_progress 是我的目标。

import os
import shutil


def progress_percentage(perc, width=None):
    # This will only work for python 3.3+ due to use of
    # os.get_terminal_size the print function etc.

    FULL_BLOCK = '█'
    # this is a gradient of incompleteness
    INCOMPLETE_BLOCK_GRAD = ['░', '▒', '▓']

    assert(isinstance(perc, float))
    assert(0. <= perc <= 100.)
    # if width unset use full terminal
    if width is None:
        width = os.get_terminal_size().columns
    # progress bar is block_widget separator perc_widget : ####### 30%
    max_perc_widget = '[100.00%]' # 100% is max
    separator = ' '
    blocks_widget_width = width - len(separator) - len(max_perc_widget)
    assert(blocks_widget_width >= 10) # not very meaningful if not
    perc_per_block = 100.0/blocks_widget_width
    # epsilon is the sensitivity of rendering a gradient block
    epsilon = 1e-6
    # number of blocks that should be represented as complete
    full_blocks = int((perc + epsilon)/perc_per_block)
    # the rest are "incomplete"
    empty_blocks = blocks_widget_width - full_blocks

    # build blocks widget
    blocks_widget = ([FULL_BLOCK] * full_blocks)
    blocks_widget.extend([INCOMPLETE_BLOCK_GRAD[0]] * empty_blocks)
    # marginal case - remainder due to how granular our blocks are
    remainder = perc - full_blocks*perc_per_block
    # epsilon needed for rounding errors (check would be != 0.)
    # based on reminder modify first empty block shading
    # depending on remainder
    if remainder > epsilon:
        grad_index = int((len(INCOMPLETE_BLOCK_GRAD) * remainder)/perc_per_block)
        blocks_widget[full_blocks] = INCOMPLETE_BLOCK_GRAD[grad_index]

    # build perc widget
    str_perc = '%.2f' % perc
    # -1 because the percentage sign is not included
    perc_widget = '[%s%%]' % str_perc.ljust(len(max_perc_widget) - 3)

    # form progressbar
    progress_bar = '%s%s%s' % (''.join(blocks_widget), separator, perc_widget)
    # return progressbar as string
    return ''.join(progress_bar)


def copy_progress(copied, total):
    print('\r' + progress_percentage(100*copied/total, width=30), end='')


def copyfile(src, dst, *, follow_symlinks=True):
    """Copy data from src to dst.

    If follow_symlinks is not set and src is a symbolic link, a new
    symlink will be created instead of copying the file it points to.

    """
    if shutil._samefile(src, dst):
        raise shutil.SameFileError("{!r} and {!r} are the same file".format(src, dst))

    for fn in [src, dst]:
        try:
            st = os.stat(fn)
        except OSError:
            # File most likely does not exist
            pass
        else:
            # XXX What about other special files? (sockets, devices...)
            if shutil.stat.S_ISFIFO(st.st_mode):
                raise shutil.SpecialFileError("`%s` is a named pipe" % fn)

    if not follow_symlinks and os.path.islink(src):
        os.symlink(os.readlink(src), dst)
    else:
        size = os.stat(src).st_size
        with open(src, 'rb') as fsrc:
            with open(dst, 'wb') as fdst:
                copyfileobj(fsrc, fdst, callback=copy_progress, total=size)
    return dst


def copyfileobj(fsrc, fdst, callback, total, length=16*1024):
    copied = 0
    while True:
        buf = fsrc.read(length)
        if not buf:
            break
        fdst.write(buf)
        copied += len(buf)
        callback(copied, total=total)


def copy_with_progress(src, dst, *, follow_symlinks=True):
    if os.path.isdir(dst):
        dst = os.path.join(dst, os.path.basename(src))
    copyfile(src, dst, follow_symlinks=follow_symlinks)
    shutil.copymode(src, dst)
    return dst

不，这不可能这样做，因为 shutil.copy 没有任何提供进步的方法。

但是你可以编写自己的复制功能（甚至可以从中分叉代码） shutil - 注意它是包含链接的模块之一 来源 在顶部，意味着它对于示例代码和仅仅使用as-is一样有用。例如，您的函数可以将进度回调函数作为额外参数，并在每个缓冲区（或每N个缓冲区，或每N个字节，或每N秒）之后调用它。就像是：

def copy(src, dst, progress):
    # ...
    for something:
        progress(bytes_so_far, bytes_total)
        # ...
    progress(bytes_total, bytes_total)

现在，该回调仍将在后台线程中调用，而不是主线程。对于大多数GUI框架，这意味着它无法直接触摸任何GUI小部件。但是大多数GUI框架都有一种方法可以将消息从后台线程发布到主线程的事件循环中，所以只需让回调就这样做。使用Qt，您可以使用信号和插槽，与主线程中的方式完全相同;如果你不知道如何，那里有很多很棒的教程。

或者，您可以按照建议的方式执行此操作：让主线程信号通知后台线程（例如，通过发布在 queue.Queue 或触发 Event 要么 Condition）并拥有你的 copy 每次通过循环功能检查该信号并做出响应。但这似乎更复杂，反应更慢。

还有一件事：Qt有自己的线程库，您可能希望使用它而不是Python的本机，因为您可以直接将插槽连接到 QThread%