在 Python 中读取 FTP 文件内容并同时用于 Pandas 和直接

2022-01-09 00:00:00 python python-3.x pandas ftp ftplib

问题描述

我正在尝试从内存中的 FTP 服务器下载文件,将其转换为数据帧,但也将其作为字节返回.代码如下:

I am trying to download a file from an FTP server in memory, transform it to a dataframe but also return it as bytes. Code as follows:

import io
import pandas as pd
from ftplib import FTP

ftp_connection.cwd(ftp_folder)
download_file = io.BytesIO()
ftp_connection.retrbinary('RETR ' + str(file_name), download_file.write)
download_file.seek(0)
file_to_process = pd.read_csv(download_file, engine='python')

在 Stack Overflow 上搜索后,建议只读取 io 流:

After searching on Stack Overflow, the suggestion was to just read the io stream:

download_file.read()
ValueError: I/O operation on closed file.

不确定接下来要尝试什么,没有将文件写入某处并以字节形式再次读取.

Not sure what to try next, without writing the file somewhere and reading it again as bytes.


解决方案

read_csv 可能会关闭文件".所以在调用 read_csv 之前请阅读它:

read_csv probably closes the "file". So read it before you call read_csv:

download_file.seek(0)
contents = download_file.read()
download_file.seek(0)
file_to_process = pd.read_csv(download_file, engine='python')

相关文章