cannot import name 'constants' from 'TCLIService' (unknown location)

同时使用impala和pyhive链接时会报这个错误，原因是import顺序不对导致冲突。
按照以下顺序导入就不会报错了：

from pyhive import hive
from impala.dbapi import connect as impalaConn
from impala.util import as_pandas

这里顺便扔两个简单的查询方法：

def selectFromImpala(sql):
    ipaddr = config["hive"]["ipaddress"]
    port = config["hive"]["port"]
    username = config["hive"]["username"]
    conn = impalaConn(host=ipaddr, port=int(port))
    cursor = conn.cursor(user=username)
    cursor.execute(sql)
    df = as_pandas(cursor)
    cursor.close()
    conn.close()
    return df

def selectFromHive(sql):
    hostname = config["hive"]["hostname"]
    port = config["hive"]["port"]
    username = config["hive"]["username"]
    conn = hive.connect(host=hostname,
                        port=port,
                        username=username)
    df = pd.read_sql(sql, conn)
    columns = df.columns
    columns_dict = {column: column.split('.')[-1] for column in columns}
    df.rename(columns=columns_dict, inplace=True)
    conn.close()
    return df