如何在文件中部插入信息
1 2 3 4 5 6 7 8 9 | 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() |
结果：
“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”
a new line
}
实现在文本指定位置插入内容
1. 场景
生产环境需要对大量的json文件进行写操作，在指定节点中插入一个属性。如下：
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 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 | { "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" }} |
需要在最后的properties节点中添加一个”druidBeam.randomizeTaskId”:”true”属性。
2. 思路
大概的思路如下：
- 扫描文件夹下所有需要更改的文件
- 在文件中确认需要更改的位置
- 插入新的字符
我觉得稍微有点难的地方是在确认插入位置的地方。我们知道的是”druid.selectors.indexing.serviceName”:”druid/overlord”,这个东西肯定在这个节点中，那我只要能找到这个东西，然后在他的后面 插入就OK了。
好了，思路已经有了，写代码吧。
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 26 27 28 29 30 31 32 33 34 35 | #!/usr/bin/python# coding:utf-8import osold_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: passdef 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: passif __name__ == '__main__': files = os.listdir('/home/tranquility/conf/service_bak') os.chdir('/home/tranquility/conf/service_bak') for file in files: insertrandomproperty(file) |
就是在内存中更新内容，然后重新写回到文件中。代码只是粗略的表达了思路，可以根据需求继续修改优化。
以上为个人经验，希望能给大家一个参考，也希望大家多多支持IT俱乐部。
