Python操作hdfs

Posted 2020-10-18 Blue眼泪2016

Python直接操作hdfs,包括追加数据文件到hdfs文件

#!coding:utf-8
import sys 
from hdfs.client import Client

#设置utf-8模式
reload(sys)
sys.setdefaultencoding( "utf-8" )

#关于python操作hdfs的API可以查看官网:
#https://hdfscli.readthedocs.io/en/latest/api.html

    
#读取hdfs文件内容,将每行存入数组返回
def read_hdfs_file(client,filename):
    #with client.read(‘samples.csv‘, encoding=‘utf-8‘, delimiter=‘\n‘) as reader:
    #  for line in reader:
    #pass
    lines = []
    with client.read(filename, encoding=‘utf-8‘, delimiter=‘\n‘) as reader:
        for line in reader:
            #pass
            #print line.strip()
            lines.append(line.strip())
    return lines
    
#创建目录
def mkdirs(client,hdfs_path) :
    client.makedirs(hdfs_path)
 
#删除hdfs文件
def delete_hdfs_file(client,hdfs_path):
    client.delete(hdfs_path)
    
#上传文件到hdfs
def put_to_hdfs(client,local_path,hdfs_path):
    client.upload(hdfs_path, local_path,cleanup=True)
    
#从hdfs获取文件到本地
def get_from_hdfs(client,hdfs_path,local_path):
    download(hdfs_path, local_path, overwrite=False)

#追加数据到hdfs文件    
def append_to_hdfs(client,hdfs_path,data):
    client.write(hdfs_path, data,overwrite=False,append=True)
    
#覆盖数据写到hdfs文件
def write_to_hdfs(client,hdfs_path,data):
    client.write(hdfs_path, data,overwrite=True,append=False)
  
#移动或者修改文件  
def move_or_rename(client,hdfs_src_path, hdfs_dst_path):
    client.rename(hdfs_src_path, hdfs_dst_path)
   
#返回目录下的文件
def list(client,hdfs_path):
    return client.list(hdfs_path, status=False)
 
#client = Client(url, root=None, proxy=None, timeout=None, session=None) 
#client = Client("http://hadoop:50070")
   
#move_or_rename(client,‘/input/2.csv‘, ‘/input/emp.csv‘)
#read_hdfs_file(client,‘/input/emp.csv‘)
#put_to_hdfs(client,‘/home/shutong/hdfs/1.csv‘,‘/input/‘)
#append_to_hdfs(client,‘/input/emp.csv‘,‘我爱你‘+‘\n‘)
#write_to_hdfs(client,‘/input/emp.csv‘,‘我爱你‘+‘\n‘)
#read_hdfs_file(client,‘/input/emp.csv‘)
#move_or_rename(client,‘/input/emp.csv‘, ‘/input/2.csv‘)
#mkdirs(client,‘/input/python‘)
#print list(client,‘/input/‘)
#chown(client,‘/input/1.csv‘, ‘root‘)