在Python中显示FTP下载进度(ProgressBar)

我使用以下Python脚本通过FTP下载文件.我想要的是在下载时查看进度的详细信息.为此,我使用了ProgressBar但它没有显示任何内容.

这是我的代码：

import re
import os
import ftplib
import ntpath

import sys
import time

from progressbar import AnimatedMarker, Bar, BouncingBar, Counter, ETA, \
    AdaptiveETA, FileTransferSpeed, FormatLabel, Percentage, \
    ProgressBar, ReverseBar, RotatingMarker, \
    SimpleProgress, Timer, UnknownLength

ftp = ftplib.FTP("Your IP address")
ftp.login("Username", "password")
files = []

try:
    ftp.cwd("/feed_1")
    files = ftp.nlst()
    for fname in files:
        res = re.findall("2018-07-25", fname)
        if res:
            print 'Opening local file ' + ntpath.basename(fname)
            file = open(ntpath.basename(fname), 'wb')
            print 'Getting ' + ntpath.basename(fname)

            try:
                 widgets = ['Downloading: ', Percentage(), ' ',
                    Bar(marker='#',left='[',right=']'),
                    ' ', ETA(), ' ', FileTransferSpeed()]

                 pbar = ProgressBar(widgets=widgets, maxval=500)
                 pbar.start()
                 ftp.retrbinary('RETR ' + ntpath.basename(fname), file.write)

            except:
                pass

            print 'Closing file ' + ntpath.basename(fname)
            file.close() 
            print (fname)
            time.sleep(0.2)
            pbar.update()
            pbar.finish() 

        if not res:
            continue

except ftplib.error_perm , resp:
    if str(resp) == "550 No files found":
        print "No files in this directory"
        pass
    else:
        raise

请帮助理解这里的实际错误.谢谢 ：)

解决方法:

您永远不会更新ProgressBar.你需要做的是：

>实现一个函数(或类方法),您将传递给FTP.retrbinary作为回调而不是file.write.该函数应该执行file.write并更新进度条.
>您还需要知道ProgressBar的maxval参数的文件/传输大小.为此你可以使用FTP.size.

一个简单的实现就像：

local_path = "archive.zip"
remote_path = "/remote/path/archive.zip"

file = open(local_path, 'wb')

size = ftp.size(remote_path)

pbar = ProgressBar(widgets = widgets, maxval = size)
pbar.start()

def file_write(data):
   file.write(data) 
   global pbar
   pbar += len(data)

ftp.retrbinary("RETR " + remote_path, file_write)

现在你得到了你想要的进度条：

Downloading:  72% [###############################            ] ETA:   0:00:00 242.1 MiB/s

其他人注意：OP代码使用progressbar2 library.

标签：python,download,ftp,ftplib,progress-bar
来源： https://codeday.me/bug/20191001/1839874.html