python中如何给文本追加内容,python写文件追加 按行追加
这篇文章主要介绍了大蟒如何匹配文本并在其上一行追加文本，具有很好的参考价值，希望对大家有所帮助。如有错误或未考虑完全的地方，望不吝赐教
目录
匹配文本并在其上一行追加文本问题描述对比遇到的坑用正则表达式匹配文本(Python经典编程案例)
匹配文本并在其上一行追加文本
问题描述
大蟒匹配文本并在其上一行追加文本
测试.文本文件（textfile）
一
乙等
英语字母表中第三个字母
拥有
英语字母表中第五个字母
1.读进列表后覆盖原文件
定义match_then_insert(文件名，匹配，内容):
匹配后在该行追加
:参数文件名：要操作的文件
:参数匹配：匹配内容
:参数内容：追加内容
线条=打开(文件名)。阅读()。分割线()
index=lines.index(匹配)
lines.insert(索引，内容)
open(filename，mode=w ).写( \n .连接(线条))
match_then_insert(test.txt ，match=c ，content=123 )
效果
一
乙等
123
英语字母表中第三个字母
拥有
英语字母表中第五个字母
2.FileInput类
从文件输入导入文件输入
定义match_then_insert(文件名，匹配，内容):
匹配后在该行追加
:参数文件名：要操作的文件
:参数匹配：匹配内容
:参数内容：追加内容
对于文件输入中的行(filename，inplace=True): #原地过滤
如果匹配行：
line=content \n line
print(line，end=) #输出重定向到原文件
match_then_insert(test.txt ，match=c ，content=123 )
3.seek
定义match_then_insert(文件名，匹配，内容):
匹配后在该行追加
:参数文件名：要操作的文件
:参数匹配：匹配内容
:参数内容：追加内容
用打开(文件名，模式=rb )作为f:
而True:
尝试：
line=f.readline() #逐行读取
除了IndexError: #超出范围则退出
破裂
line_str=line.decode().分割线()[0]
if line_str==match:
f.seek(-len(line)，1) #光标移动到上一行
rest=f.read() #读取余下内容
f.seek(-len(rest)，1) #光标移动回原位置
f.truncate() #删除余下内容
content=content \n
f.write(content.encode()) #插入指定内容
f.write(rest) # 还原余下内容
break
match_then_insert(test.txt, match=c, content=123)
对比
方案 耗时/s
from timeit import timeitfrom fileinput import FileInput
def init_txt():
open(test.txt, mode=w).write(\n.join([a, b, c, d, e]))
def f1(filename=test.txt, match=c, content=123):
lines = open(filename).read().splitlines()
index = lines.index(match)
lines.insert(index, content)
open(filename, mode=w).write(\n.join(lines))
def f2(filename=test.txt, match=c, content=123):
for line in FileInput(filename, inplace=True):
if match in line:
line = content + \n + line
print(line, end=)
def f3(filename=test.txt, match=c, content=123):
with open(filename, mode=rb+) as f:
while True:
try:
line = f.readline()
except IndexError:
break
line_str = line.decode().splitlines()[0]
if line_str == match:
f.seek(-len(line), 1)
rest = f.read()
f.seek(-len(rest), 1)
f.truncate()
content = content + \n
f.write(content.encode())
f.write(rest)
break
init_txt()
print(timeit(f1, number=1000))
init_txt()
print(timeit(f2, number=1000))
init_txt()
print(timeit(f3, number=1000))
遇到的坑
报错可试试在文件头部添加
# -*- coding: utf-8 -*-
或指定 encoding='utf-8'
用正则表达式匹配文本(Python经典编程案例)
ceshi.txt文本如下：第一行为空行
爬虫任务报警
01:45:21
scrapyd==》爬虫任务异常死亡报警
hostname: scrapyd-chinabond-1
error_count: Process died: exitstatus=None ,project: chinabond_fast_spider,spider: ah_sina_com_cn,job: 28395818dbcb11e998a3f632d94e247c,pid: 88971,log: data/logs/chinabond_fast_spider/ah_sina_com_cn/28395818dbcb11e998a3f632d94e247c.log,items: None
error_data:
爬虫任务报警
01:45:21
scrapyd==》爬虫任务异常死亡报警
hostname: scrapyd-chinabond-6
error_count: Process died: exitstatus=None ,project: chinabond_fast_spider,spider: shupeidian_bjx_com_cn,job: 04738a5cdbcb11e9803172286b76aa73,pid: 34246,log: data/logs/chinabond_fast_spider/shupeidian_bjx_com_cn/04738a5cdbcb11e9803172286b76aa73.log,items: None
error_data:
爬虫任务报警
01:45:21
scrapyd==》爬虫任务异常死亡报警
hostname: scrapyd-chinabond-6
error_count: Process died: exitstatus=None ,project: chinabond_fast_spider,spider: news_sdchina_com,job: 28e8db4edbcb11e9803172286b76aa73,pid: 34324,log: data/logs/chinabond_fast_spider/news_sdchina_com/28e8db4edbcb11e9803172286b76aa73.log,items: None
error_data:
爬虫任务报警
01:47:20
scrapyd==》爬虫任务异常死亡报警
hostname: scrapyd-chinabond-0
error_count: Process died: exitstatus=None ,project: chinabond_fast_spider,spider: hq_smm_cn,job: 4bdc3af6dbcb11e9a45522b8c8b2a9e4,pid: 111593,log: data/logs/chinabond_fast_spider/hq_smm_cn/4bdc3af6dbcb11e9a45522b8c8b2a9e4.log,items: None
error_data:
爬虫任务报警
01:47:21
scrapyd==》爬虫任务异常死亡报警
hostname: scrapyd-chinabond-6
error_count: Process died: exitstatus=None ,project: chinabond_fast_spider,spider: sichuan_scol_com_cn,job: 71321c4edbcb11e9803172286b76aa73,pid: 34461,log: data/logs/chinabond_fast_spider/sichuan_scol_com_cn/71321c4edbcb11e9803172286b76aa73.log,items: None
error_data:
爬虫任务报警
01:47:21
scrapyd==》爬虫任务异常死亡报警
hostname: scrapyd-chinabond-2
error_count: Process died: exitstatus=None ,project: chinabond_fast_spider,spider: www_mof_gov_cn,job: 7418dacedbcb11e9b15e02034af50b6e,pid: 65326,log: data/logs/chinabond_fast_spider/www_mof_gov_cn/7418dacedbcb11e9b15e02034af50b6e.log,items: None
error_data:
爬虫任务报警
01:47:21
scrapyd==》爬虫任务异常死亡报警
hostname: scrapyd-chinabond-5
error_count: Process died: exitstatus=None ,project: chinabond_fast_spider,spider: www_funxun_com,job: 4dcda7a0dbcb11e980a8862f09ca6d70,pid: 27785,log: data/logs/chinabond_fast_spider/www_funxun_com/4dcda7a0dbcb11e980a8862f09ca6d70.log,items: None
error_data:
爬虫任务报警
01:49:21
scrapyd==》爬虫任务异常死亡报警
hostname: scrapyd-chinabond-4
error_count: Process died: exitstatus=None ,project: chinabond_fast_spider,spider: shuidian_bjx_com_cn,job: 95090682dbcb11e9a0fade28e59e3773,pid: 106424,log: data/logs/chinabond_fast_spider/shuidian_bjx_com_cn/95090682dbcb11e9a0fade28e59e3773.log,items: None
error_data:
爬虫任务报警
01:51:20
scrapyd==》爬虫任务异常死亡报警
hostname: scrapyd-chinabond-0
error_count: Process died: exitstatus=None ,project: chinabond_fast_spider,spider: tech_sina_com_cn,job: de4bdf72dbcb11e9a45522b8c8b2a9e4,pid: 111685,log: data/logs/chinabond_fast_spider/tech_sina_com_cn/de4bdf72dbcb11e9a45522b8c8b2a9e4.log,items: None
error_data:
爬虫任务报警
01:51:21
scrapyd==》爬虫任务异常死亡报警
hostname: scrapyd-chinabond-6
error_count: Process died: exitstatus=None ,project: chinabond_fast_spider,spider: ee_ofweek_com,job: ff6bd5b8dbcb11e9803172286b76aa73,pid: 34626,log: data/logs/chinabond_fast_spider/ee_ofweek_com/ff6bd5b8dbcb11e9803172286b76aa73.log,items: None
error_data:
爬虫任务报警
01:51:21
scrapyd==》爬虫任务异常死亡报警
hostname: scrapyd-chinabond-6
error_count: Process died: exitstatus=None ,project: chinabond_fast_spider,spider: house_hexun_com,job: ff6dfdacdbcb11e9803172286b76aa73,pid: 34633,log: data/logs/chinabond_fast_spider/house_hexun_com/ff6dfdacdbcb11e9803172286b76aa73.log,items: None
error_data:
爬虫任务报警
01:51:21
scrapyd==》爬虫任务异常死亡报警
hostname: scrapyd-chinabond-2
error_count: Process died: exitstatus=None ,project: chinabond_fast_spider,spider: www_sjfzxm_com,job: 018e7d78dbcc11e9b15e02034af50b6e,pid: 65492,log: data/logs/chinabond_fast_spider/www_sjfzxm_com/018e7d78dbcc11e9b15e02034af50b6e.log,items: None
error_data:
爬虫任务报警
01:53:21
scrapyd==》爬虫任务异常死亡报警
hostname: scrapyd-chinabond-4
error_count: Process died: exitstatus=None ,project: chinabond_fast_spider,spider: news_xianzhaiwang_cn,job: 48d835e8dbcc11e9a0fade28e59e3773,pid: 106476,log: data/logs/chinabond_fast_spider/news_xianzhaiwang_cn/48d835e8dbcc11e9a0fade28e59e3773.log,items: None
error_data:
代码如下：
import osimport re
import json
from collections import namedtuple
alert = namedtuple(Spider_Alert, alert_time, alert_hostname, alert_project, alert_spider)
path = rD:\data\ceshi.txt
g_path = rD:\data\\
file_name = rresult.txt
file_path = g_path + file_name
alerts_list = list()
with open(path, encoding="utf-8") as file:
lines = file.readlines() # 读取每一行
count = 0
time = None
hostname = None
project = None
for line in lines:
if re.search(r^\d{2}:\d{2}:\d{2}\s*$, line):
time = re.search(r^(\d{2}:\d{2}:\d{2})\s*$, line).group(1)
if re.search(r^hostname:\s*(.+), line):
hostname = re.search(r^hostname:\s*(.+), line).group(1)
if re.search(rproject:\s*([^,]+),, line):
project = re.search(rproject:\s*([^,]+),, line).group(1)
if re.search(rspider:\s*([^,]+),, line):
spider = re.search(rspider:\s*([^,]+),, line).group(1)
if re.search(r^error_data, line):
spider_alert = None
spider_alert = alert(alert_time=time, alert_hostname=hostname, alert_project=project, alert_spider=spider)
alerts_list.append(spider_alert)
for element in alerts_list:
print(element[0], element[1], element[3])
with open(file_path, a, encoding="utf-8") as file:
file.write(element[0] + "\t" + element[1] + "\t" + element[3])
file.write( \n)
执行结果如下图：
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