1. Output logs to files

Use module: logging

You can generate custom level logs and output logs to the specified path
Log level: debug (debug log)

1. Encapsulation log Output method ()

import logging as lg
import os

class logging_():
    def __init__(path,delete=True)
        self.path = path #日志文件存放位置
        name = 'log.log' #日志文件名稱
        self.log_ = os.path.join(self.path,name) #進入文件目錄
        if delete == True：
            open(f"{path}/{name}","w").close #為True時清空文本
        # 創(chuàng)建一個日志處理器
        self.logger = lg.getLogger('logger')
        # 設置日志等級，低于設置等級的日志被丟棄
        self.logger.setLevel(lg.DEBUG)
        # 設置輸出日志格式
        self.fmt = lg.Formatter("[%(asctime)s] - %(levelname)s: %(message)s","%Y-%m-%d %H:%M:%S")  
        # 創(chuàng)建一個文件處理器
        self.fh = lg.FileHandler(self.log_,encoding='utf-8')
        # 設置文件輸出格式
        self.fh.setFormatter(self.fmt)
        # 將文件處理器添加到日志處理器中
        self.logger.addHandler(self.fh)
        # 創(chuàng)建一個控制臺處理器
        self.sh=lg.StreamHandler()
        # 設置控制臺輸出格式
        self.sh.setFormatter(self.fmt)
        # 將控制臺處理器添加到日志處理器中
        self.logger.addHandler(self.sh)
        
        # 關閉文件
        self.fh.close()
        
# 使用
if __name__ == '__main__':
    _path = os.paht.dirname(__file__) # 獲取當前文件的路徑
    lg = logging_(_path).logger # 實例化封裝類
    lg.info('1111')
    lg.debug('2222')
    lg.error('33333')
    lg.warning('44444')

Output content after running, there is an additional log.log file in the current file directory:

Log content:

2. Generate logs and read logs

1. Create a new py file (generation_log) with a customized file name.

2. Directly upload Code

# 導入上面封裝好的日志輸出
from logging.demo_01 import logging_
import os，time
_path = os.path.dirname(__file__) # 獲取當前文件路徑
lg = logging_(_path) # 實例化類

# 創(chuàng)建方法生成日志
def generation_log():    
    for i in range(20):
        lg.info(i)
        time.sleep(1)
        
# 讀取日志并返回
def red_logs():
    log_path = f'{_path}/log.log' # 獲取日志文件路徑
    with open(log_path,'rb') as f:
        log_size = path.getsize(log_path) # 獲取日志大小
        offset = -100
        # 如果文件大小為0時返回空
        if log_size == 0:
            return ''
        while True:
            # 判斷offset是否大于文件字節(jié)數(shù),是則讀取所有行,并返回
            if (abs(offset) >= log_size):
                f.seek(-log_size, 2)
                data = f.readlines()
                return data
            # 游標移動倒數(shù)的字節(jié)數(shù)位置
            data = f.readlines()
            # 判斷讀取到的行數(shù)，如果大于1則返回最后一行，否則擴大offset
            if (len(data) > 1):
                return data
            else:
                offset *= 2

3. Flask creates a web service

I won’t explain what flask does right now. If you are interested, you can go to Baidu or wait for my update. Here, just follow the steps and add the code. Quickly implement a simple web page

1. Create an app.py file in the directory and enter the following code

#導入flask模塊
from flask import Flask,request,render_template
# 導入日志生成和日志返回方法
from study.logging.generation_log import generation_log,red_logs

app = Flask(__name__)

line_number = [0] #存放當前日志行數(shù)
# 定義接口把處理日志并返回到前端
@app.route('/get_log',methods=['GET','POST'])
def get_log():
    log_data = red_logs() # 獲取日志
    # 判斷如果此次獲取日志行數(shù)減去上一次獲取日志行數(shù)大于0，代表獲取到新的日志
    if len(log_data) - line_number[0] > 0:
        log_type = 2 # 當前獲取到日志
        log_difference = len(log_data) - line_number[0] # 計算獲取到少行新日志
        log_list = [] # 存放獲取到的新日志
        # 遍歷獲取到的新日志存放到log_list中
        for i in range(log_difference):
            log_i = log_data[-(i+1)].decode('utf-8') # 遍歷每一條日志并解碼
            log_list.insert(0,log_i) # 將獲取的日志存放log_list中
    else:
        log_type = 3
        log_list = ''
    # 已字典形式返回前端
    _log = {
        'log_type' : log_type,
        'log_list' : log_list
    }
    line_number.pop() # 刪除上一次獲取行數(shù)
    line_number.append(len(log_data)) # 添加此次獲取行數(shù)
    return _log

# 通過前端請求執(zhí)行生成日志方法
@app.route('/generation_log',methods=['GET','POST'])
def generation_log_():
    if request.method == 'POST':
        generation_log()
    return ''

@app.route('/',methods=['GET','POST'])
def index():
    if request.method == 'GET':
        return render_template('index.html')
    if request.method == 'POST':
        return render_template('index.html')

if __name__ == "__main__":
    app.run(debug=True) #啟動web服務

2. Create a templates directory in the directory

3. Create a new index.html file in the templates directory and enter the following front-end code

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        body{
            margin: auto;
            background-color: #f5f5f5;
        }
        .button{width: 200px;height: 50px;color:#FFFFFF;background-color: #1da1f2}
        .log{
            width: 98%;
            height: 500px;
            background-color: #FFFFFF;
            margin: 0 auto;
            margin-top: 10px;
            padding-top: 30px;
            padding-bottom: 40px;
        }
        .log_text{
            height: 500px;
            margin-left: 80px;
            font-size: 18px;
            color: #111111;
            overflow-x: hidden;
            overflow-y: auto;
        }
    </style>
</head>
<body>
<button id="button" class="button">開始</button>
<div class="log">
    <div class="log_text" id=&#39;log_list&#39;>
        <div id="log_text"></div>
    </div>
</div>
</body>

<script src="http://libs.baidu.com/jquery/2.0.0/jquery.min.js"></script>
<script>
    var time
      // 創(chuàng)建一個元素節(jié)點
    function insertAfter( newElement, targetElement ){ // newElement是要追加的元素targetElement 是指定元素的位置
        var parent = targetElement.parentNode; // 找到指定元素的父節(jié)點
        parent.appendChild( newElement, targetElement );
    };
    function log(){
        clearTimeout(time) // 清空定時器
        var log_null = 0 //存放空日志次數(shù)
        var div = document.getElementById(&#39;log_list&#39;) //找到存放日志的塊
        div.innerHTML = "<div id=&#39;log_text&#39;></div>" // 每次跑清空div內內容

        $.post(&#39;/generation_log&#39;,{},function (){
        }) //請求生成日志接口
        // 生成定時器
        time = setInterval(function (){
            $.get(&#39;/get_log&#39;,{},function (data){ //請求獲取日志接口獲取日志
                if (data.log_type == 3){ //如果獲取的是空日志log_null次數(shù)加1
                    log_null ++
                    if (log_null >= 5){
                        clearTimeout(time) //如果連續(xù)10次獲取的都是空日志清除定時任務
                    }
                    return
                }
                if (data.log_type == 2){ //如果獲取到新日志
                    for (i=0;i<data.log_list.length;i++){ //遍歷日志
                        var p = document.createElement("p") //生成一個p標簽
                        p.innerHTML = data.log_list[i] //日志存放到P標簽內
                        var header = document.getElementById(&#39;log_text&#39;)
                        insertAfter(p,header) //將p標簽添加到log_text div中
                        div.scrollTop = div.scrollHeight //滾動條實時顯示到底部
                    }
                    log_null = 0 //日志為空次數(shù)清0
                }

            })
        },1000) //每1秒鐘執(zhí)行一次
    }
    document.getElementById(&#39;button&#39;).addEventListener("click",log) //點擊開始按鈕開始執(zhí)行
</script>
</html>

4. Start the service

1. Check the project directory to see if the code is complete

2. Start the app.py file

3. Access the local connection: http://127.0.0.1:5000/

##4 , click start

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