pyhon-在原文本文件中替换某些特定的字符

# coding:utf-8# 20170718_N.csv 文件的格式为：# "1",2,3,"4","5",6,"7",8,9,10,11,12,13,14,15,"16",17,18,19,20,21,22,23,24，25# 要求将前23个","号替换为"|",且在原文件中进行修改op = open('20170718_N.csv', 'r+')line_tell = 0for line in op:    count = 0    for i in line:        line_tell += 1        op.seek(line_tell, 0)        if i == ',':            if count >= 23:                break            else:                op.seek(line_tell - 1, 0)                op.write("|")                count += 1        else:            continueop.close()