問題描述
我想檢索存儲(chǔ)在 FTP 服務(wù)器上的壓縮 gz 文件中的數(shù)據(jù)，而不將文件寫入本地存檔.
I would like to retrieve the data inside a compressed gz file stored on an FTP server, without writing the file to the local archive.
目前我已經(jīng)完成了
from ftplib import FTP
import gzip
ftp = FTP('ftp.server.com')
ftp.login()
ftp.cwd('/a/folder/')
fileName = 'aFile.gz'
localfile = open(fileName,'wb')
ftp.retrbinary('RETR '+fileName, localfile.write, 1024)
f = gzip.open(localfile,'rb')
data = f.read()
然而，這會(huì)將文件localfile"寫入當(dāng)前存儲(chǔ).
This, however, writes the file "localfile" on the current storage.
我試圖改變這個(gè)
from ftplib import FTP
import zlib
ftp = FTP('ftp.server.com')
ftp.login()
ftp.cwd('/a/folder/')
fileName = 'aFile.gz'
data = ftp.retrbinary('RETR '+fileName, zlib.decompress, 1024)
但是，ftp.retrbinary 不輸出其回調(diào)的輸出.有沒有辦法做到這一點(diǎn)?
but, ftp.retrbinary does not output the output of its callback.
Is there a way to do this?
推薦答案
一個(gè)簡單的實(shí)現(xiàn)是:
將文件下載到內(nèi)存中類似文件的對象，例如
BytesIO;
將其傳遞給 fileobj 參數(shù)noreferrer">GzipFile 構(gòu)造函數(shù).
pass that to fileobj parameter of GzipFile constructor.
import gzip
from io import BytesIO
import shutil
from ftplib import FTP
ftp = FTP('ftp.example.com')
ftp.login('username', 'password')
flo = BytesIO()
ftp.retrbinary('RETR /remote/path/archive.tar.gz', flo.write)
flo.seek(0)
with open('archive.tar', 'wb') as fout, gzip.GzipFile(fileobj = flo) as gzip:
shutil.copyfileobj(gzip, fout)
<小時(shí)>
以上將整個(gè) .gz 文件加載到內(nèi)存中.對于大文件來說什么是低效的.更智能的實(shí)現(xiàn)將改為流式傳輸數(shù)據(jù).但這可能需要實(shí)現(xiàn)一個(gè)智能的自定義類文件對象.
The above loads whole .gz file to a memory. What can be inefficient for large files. A smarter implementation would stream the data instead. But that would probably require implementing a smart custom file-like object.
另請參閱在 FTP 服務(wù)器上的 zip 文件中獲取文件名，而無需下載整個(gè)存檔.
這篇關(guān)于從 FTP 服務(wù)器上的 gz 文件中檢索數(shù)據(jù)而不在本地寫入的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網(wǎng)！