Python example to download files from an anonymous FTP server (example case from 1000 Genomes)

download-1000-genomes-vcf.py

#!/usr/bin/env python

from __future__ import print_function
import ftplib, datetime, sys

# ftp://ftp.1000genomes.ebi.ac.uk/vol1/ftp/release/20130502/ALL.chr14.phase3_shapeit2_mvncall_integrated_v5a.20130502.genotypes.vcf.gz

def log(msg):
    timestamp = datetime.datetime.now().strftime("%Y-%m-%d %T")
    print('[-- {} --] {}'.format(timestamp, msg), file=sys.stderr)

server = 'ftp.1000genomes.ebi.ac.uk'
directory = 'vol1/ftp/release/20130502'

vcf = 'ALL.chr14.phase3_shapeit2_mvncall_integrated_v5a.20130502.genotypes.vcf.gz.tbi'

log("connecting to server")
ftp = ftplib.FTP(server)
ftp.login()

log("changing to directory: {}".format(directory))
ftp.cwd(directory)
ftp.retrlines('LIST')

log("starting to download: {}".format(vcf))
ftp.retrbinary("RETR {}".format(vcf), open(vcf, 'wb').write)
log("finished download")

ftp.quit()