python如何在文件中部插入信息

fp = open('D://代码开发//Python.path//jhp//fadd.txt', 'r')           #指定文件 s = fp.read()                   #将指定文件读入内存 fp.close()                      #关闭该文件 a = s.split('\n') a.insert(-1, 'a new line')    #在第 LINE+1 行插入 s = '\n'.join(a)                #用'\n'连接各个元素 fp = open('D://代码开发//Python.path//jhp//fadd.txt', 'w') fp.write(s) fp.close()

{ "dataSources":{ "test_dataSource_hod":{ "spec":{ "dataSchema":{ "dataSource":"test_dataSource_hod", "parser":{ "type":"string", "parseSpec":{ "timestampSpec":{ "column":"timestamp", "format":"yyyy-MM-dd HH:mm:ss" }, "dimensionsSpec":{ "dimensions":[ "method", "key" ] }, "format":"json" } }, "granularitySpec":{ "type":"uniform", "segmentGranularity":"hour", "queryGranularity":"none" }, "metricsSpec":[ { "name":"count", "type":"count" }, { "name":"call_count", "type":"longSum", "fieldName":"call_count" }, { "name":"succ_count", "type":"longSum", "fieldName":"succ_count" }, { "name":"fail_count", "type":"longSum", "fieldName":"fail_count" } ] }, "ioConfig":{ "type":"realtime" }, "tuningConfig":{ "type":"realtime", "maxRowsInMemory":"100000", "intermediatePersistPeriod":"PT10M", "windowPeriod":"PT10M" } }, "properties":{ "task.partitions":"1", "task.replicants":"1", "topicPattern":"test_topic" } } }, "properties":{ "zookeeper.connect":"zookeeper.com:2015", "druid.discovery.curator.path":"/druid/discovery", "druid.selectors.indexing.serviceName":"druid/overlord", "commit.periodMillis":"12500", "consumer.numThreads":"1", "kafka.zookeeper.connect":"kafkaka.com:2181,kafka.com:2181,kafka.com:2181", "kafka.group.id":"test_dataSource_hod_dd" } } 

#!/usr/bin/python # coding:utf-8 import os old_string = '"druid/overlord"' new_string = ('"druid/overlord",' + '\n        ' + '"druidBeam.randomizeTaskId":"true",') def insertrandomproperty(file_name): if '.json' in file_name: with open(file, 'r') as oldfile: content = oldfile.read() checkandinsert(content, file) else: pass def checkandinsert(content, file): if 'druidBeam.randomizeTaskId' not in content: # to avoid ^M appear in the new file because of different os # we replace \r  with '' new_content = content.replace(old_string, new_string).replace('\r', '') with open(file, 'w') as newfile: newfile.write(new_content) else: pass if __name__ == '__main__': files = os.listdir('/home/tranquility/conf/service_bak') os.chdir('/home/tranquility/conf/service_bak') for file in files: insertrandomproperty(file)