Data analysis using python
1: How to parse data in json format
import json,os,sys current_dir=os.path.abspath(".") filename=[file for file in os.listdir(current_dir) if ".txt" in file]#得到当前目录中,后缀为.txt的数据文件 fn=filename[0] if len(filename)==1 else "" #从list中取出第一个文件名 if fn: # means we got a valid filename fd=open(fn) content=[json.loads(line) for line in fd] else: print("no txt file in current directory") sys.exit(1) for linedict in content: for key,value in linedict.items(): print(key,value) print("\n")
2: Occurrence frequency statistics
import random from collections import Counter fruits=[random.choice(["apple","cherry","orange","pear","watermelon","banana"]) for i in range(20)] print(fruits) #查看所有水果出现的次数 cover_fruits=Counter(fruits) for fruit,times in cover_fruits.most_common(3): print(fruit,times) ########运行结果如下:apple在fruits里出了5次 apple 5 banana 4 pear 4
3: Method of reloading module py3
import importlib import.reload(modulename)
4: Which modules are included in pylab
from pylab import *
is equivalent to the following import statement:
from pylab import * from numpy import * from scipy import * import matplotlib
The above is the detailed content of Data analysis using python. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics



PS "Loading" problems are caused by resource access or processing problems: hard disk reading speed is slow or bad: Use CrystalDiskInfo to check the hard disk health and replace the problematic hard disk. Insufficient memory: Upgrade memory to meet PS's needs for high-resolution images and complex layer processing. Graphics card drivers are outdated or corrupted: Update the drivers to optimize communication between the PS and the graphics card. File paths are too long or file names have special characters: use short paths and avoid special characters. PS's own problem: Reinstall or repair the PS installer.

A PS stuck on "Loading" when booting can be caused by various reasons: Disable corrupt or conflicting plugins. Delete or rename a corrupted configuration file. Close unnecessary programs or upgrade memory to avoid insufficient memory. Upgrade to a solid-state drive to speed up hard drive reading. Reinstalling PS to repair corrupt system files or installation package issues. View error information during the startup process of error log analysis.

"Loading" stuttering occurs when opening a file on PS. The reasons may include: too large or corrupted file, insufficient memory, slow hard disk speed, graphics card driver problems, PS version or plug-in conflicts. The solutions are: check file size and integrity, increase memory, upgrade hard disk, update graphics card driver, uninstall or disable suspicious plug-ins, and reinstall PS. This problem can be effectively solved by gradually checking and making good use of PS performance settings and developing good file management habits.

The key to feather control is to understand its gradual nature. PS itself does not provide the option to directly control the gradient curve, but you can flexibly adjust the radius and gradient softness by multiple feathering, matching masks, and fine selections to achieve a natural transition effect.

The article introduces the operation of MySQL database. First, you need to install a MySQL client, such as MySQLWorkbench or command line client. 1. Use the mysql-uroot-p command to connect to the server and log in with the root account password; 2. Use CREATEDATABASE to create a database, and USE select a database; 3. Use CREATETABLE to create a table, define fields and data types; 4. Use INSERTINTO to insert data, query data, update data by UPDATE, and delete data by DELETE. Only by mastering these steps, learning to deal with common problems and optimizing database performance can you use MySQL efficiently.

MySQL performance optimization needs to start from three aspects: installation configuration, indexing and query optimization, monitoring and tuning. 1. After installation, you need to adjust the my.cnf file according to the server configuration, such as the innodb_buffer_pool_size parameter, and close query_cache_size; 2. Create a suitable index to avoid excessive indexes, and optimize query statements, such as using the EXPLAIN command to analyze the execution plan; 3. Use MySQL's own monitoring tool (SHOWPROCESSLIST, SHOWSTATUS) to monitor the database health, and regularly back up and organize the database. Only by continuously optimizing these steps can the performance of MySQL database be improved.

MySQL has a free community version and a paid enterprise version. The community version can be used and modified for free, but the support is limited and is suitable for applications with low stability requirements and strong technical capabilities. The Enterprise Edition provides comprehensive commercial support for applications that require a stable, reliable, high-performance database and willing to pay for support. Factors considered when choosing a version include application criticality, budgeting, and technical skills. There is no perfect option, only the most suitable option, and you need to choose carefully according to the specific situation.

The loading interface of PS card may be caused by the software itself (file corruption or plug-in conflict), system environment (due driver or system files corruption), or hardware (hard disk corruption or memory stick failure). First check whether the computer resources are sufficient, close the background program and release memory and CPU resources. Fix PS installation or check for compatibility issues for plug-ins. Update or fallback to the PS version. Check the graphics card driver and update it, and run the system file check. If you troubleshoot the above problems, you can try hard disk detection and memory testing.
