#!/usr/bin/python
# -*- coding: utf-8 -*-

import os
from ftplib import FTP


# ftp 伺服器連結
def ftpconnect():
    ftp_server = 'ftp.ncdc.noaa.gov'
    username = ''
    password = ''
    ftp = FTP()
    ftp.set_debuglevel(2)  # 開啟除錯級別2，顯示詳細資訊
    ftp.connect(ftp_server, 21)  # 連線
    ftp.login(username, password)  # 登入，如果匿名登入則用空串代替即可
 

    return ftp


# 開始下載檔案
def downloadfile(start, end,srcpath):
    ftp = ftpconnect()
    # print ftp.getwelcome() #顯示ftp伺服器歡迎資訊
    datapath = "/pub/data/gsod/"
    while start <= end:
        path = datapath + str(start)
        li = ftp.nlst(path)

        # 建立指定年份的目錄
        path = srcpath + '/'
 

        dir = str(start)
        new_path = os.path.join(path, dir)
        if not os.path.isdir(new_path):
            os.makedirs(new_path)

        for eachFile in li:
            localpaths = eachFile.split("/")
            localpath = localpaths[len(localpaths) - 1]
            localpath = new_path + '/'
 
 + str(start) + '--' + localpath  # 把日期放在最前面，方便排序
            bufsize = 1024  # 設定緩衝塊大小
            fp = open(localpath, 'wb')  # 以寫模式在本地開啟檔案
            ftp.retrbinary('RETR ' + eachFile, fp.write, bufsize)  # 接收伺服器上檔案並寫入本地檔案
        start = start + 1
    ftp.set_debuglevel(0)  # 關閉除錯
    ftp.close()
    ftp.quit()  # 退出ftp伺服器


if __name__ == "__main__":
    downloadfile(1950,2017,"g:/c/ncdc")