【python】幾個常用工具函數

#!/usr/bin/env python2.7#-*- encoding: utf-8 -*-import timeimport datetimeimport MySQLdbimport osimport reimport paramiko# map的value值增量def safe_inc_map_val(map, key, val):    if key in map.keys(): map[key] = map[key] + val    else: map[key] = val# 目前時間def time_now():    return datetime.datetime.now()# 判斷檔案是否存在def check_file_exists(filename):    if not os.path.exists(filename):        return False    return True # 刪除檔案def remove_file(file_name):    if(os.path.isfile(file_name)):        os.remove(file_name)# 刪除相應目錄下的txt檔案def remove_text_file(filepath):    filelist = os.listdir(filepath)    for ele in filelist:                if ele.find('.txt')>-1:            os.remove(filepath+ele)   #IP轉化為對應整數def ip_to_int(ip):    int_val = reduce(lambda x,y:(x<<8)+y,map(int,ip.split('.')))    return int_val#IP轉化為對應整數def Ip2Int(ip):    import struct,socket    return struct.unpack("!I",socket.inet_aton(ip))[0]# 計算文字檔的行數def line_count(file_name):    count = -1 #讓空檔案的行號顯示0    for count,line in enumerate(open(file_name)): pass    #enumerate格式化成了元組,count就是行號,因為從0開始要+1    return count+1# 使用外部系統程式 wc -l， 來計算文字檔的行數def linecount_wc(file_name):    cmd = 'wc -l %s'%file_name    return int(os.popen(cmd).read().split()[0])# 遠程拷貝檔案def sftp_get(host_ip,remote_path,local_path,username,password):    t = paramiko.Transport((host_ip,22))    t.connect(username=username, password=password)    sftp = paramiko.SFTPClient.from_transport(t)    src = remote_path     des = local_path    sftp.get(src,des)    t.close()# 按行分割文字檔def split_file(filepath, file_num):        total_rows = linecount_wc(filepath)        lines = total_rows/file_num+1 #這裡大小加上1row，保證最後一個分割的檔案不會丟資料        command = " split -l%d -a2 -d %s %s" % (lines, filepath, filepath) #其實使用的就是liunx的split        #print command        os.system(command)# 按行分割文字檔，並將分割後的檔案輸出到新目錄def split_file2(filepath, new_filepath, file_num):        total_rows = linecount_wc(filepath)        lines = total_rows/file_num+1         command = " split -l%d -a2 -d %s %s" % (lines, filepath, new_filepath)         os.system(command)# 返回結果集中的int值def query_fetch_one_int(cursor, sql):    result = 0    n = cursor.execute(sql)    if (n > 0):         r = cursor.fetchone()        if r[0] != None:result = int(r[0])    return result# 返回結果集中的float值def query_fetch_one_float(cursor, sql):    result = 0    n = cursor.execute(sql)    if (n > 0):         r = cursor.fetchone()        if r[0] != None:result = float(r[0])    return result# 返回結果集中的kv值列表def query_fetch_pair_array(cursor, sql):    result = []    n = cursor.execute(sql)    if (n > 0):         ds = cursor.fetchall()        for r in ds:result.append((r[0], r[1]))    return result# 返回結果集中的一組列表def query_fetch_one_list(cursor , sql):    result = []    n = cursor.execute(sql)    if n>0:        ds = cursor.fetchall()        result = [ele[0] for ele in ds if ele!=None]    return result