Python for Data Analysis v2 | Notes_ Chapter 3 Python Data Structure, Functions and Files

I use Sean Cheney series of special articles and original books as learning resources to record personal notes, which are only used for knowledge recording and later review. The address of the original author is checked. Sean Cheney If there are any mistakes, criticism and advice are also expected. -- ZJ Original Au ...

Posted on Wed, 26 Dec 2018 11:39:07 -0800 by aim25

Common linux commands sort,uniq,cut,wc

sort The sort command sorts the rows in the file specified by the File parameter and writes the results to standard output. If the File parameter specifies multiple files, the sort command links them together and sorts them as one file. sort syntax [root@www ~]# sort [-fbMnrtuk] [file or stdin] Options and parameters: - f: Ignore the diff ...

Posted on Wed, 26 Dec 2018 10:12:06 -0800 by Bad HAL 9000

Talk about the typical use of I/O streams in Java I/O systems (with examples)

In the following examples, all exception handling is simplified to the console. In practical projects, it is recommended to add more complex error handling capabilities. 1 Read files (with buffer) If you want to open a file and read characters from it, you can use FileInputReader. But when using FileInputReader to read characters, it will ...

Posted on Mon, 24 Dec 2018 15:15:06 -0800 by ziong

My Android Advanced Journey - -->android Matrix image zoom and zoom randomly, drag and drop

Step 1: Create a new project DragAndZoom and prepare a photo to be placed in the res/drawable-hdpi directory        Step 2: Set up the UI interface of the application and set it in main.xml: [html] view plain copy print? <?xml version="1.0" encoding="utf-8"?>   <LinearLayout xmlns:android="http://schemas.androi ...

Posted on Sun, 23 Dec 2018 15:54:06 -0800 by erika_web

iOS Development runtime Principles and Practice: Basic Knowledge Papers (Classes, Superclasses, Metaclasses, Superclass, isa, Objects, Methods, SEL, IMP)

ABSTRACT: This article first introduces the principles of runtime, including the concepts of class, super class, metaclass, super_class, isa, object, method, SEL, IMP, and API related to these concepts. Then it introduces the process of method invocation and the process of finding IMP. Then, I introduce the common usage of these A ...

Posted on Sat, 22 Dec 2018 07:03:06 -0800 by VBAssassin

Number type, String type, Global object, Math object summary in JavaScript

http://blog.csdn.net/bboyjoe/article/details/51532319 Number type valueOf(): Returns the value of the basic type represented by the object. toString(): Passes a parameter representing the cardinality, telling it to return the string form of a numeric number of decimal digits. var num=10;   console.log(num.toString());/ ...

Posted on Sat, 22 Dec 2018 02:00:06 -0800 by Unseeeen

Solutions to still scrambling after response.setContentType("text/html;charset=utf-8")

From the browser to the server, the server will get the data and then display it on the browser. The problem of Chinese character scrambling has been used.   response.setContentType("text/html;charset=utf-8"); Set the browser code to utf-8, but still scramble The source code is as follows: package com.swift; import java.io.File; import java. ...

Posted on Fri, 21 Dec 2018 15:36:05 -0800 by cfgcjm

Android AudioRecord and AudioTrack realize the collection and playback of audio PCM data, and read and write audio wav files.

https://rustfisher.github.io/2018/02/24/Android_note/Android-audio_AudioRecord_AudioTrack_pcm_wav/ win7 Android Studio 3.0.1 The purpose of this paper is to use AudioRecord and AudioTrack to complete the acquisition and playback of audio PCM data, and to read and write audio wav files. Dead work Android provides AudioRecord and M ...

Posted on Thu, 20 Dec 2018 21:15:05 -0800 by the7soft.com

python tornado logging.handlers.HTTPHandler print one more None solution

1, Background: With tornado, asynchronism leads to inaccurate positioning of business logic logs, because half of the output logs are lost to other business logic, and then back to continue to output logs, which makes the logs look like: 2017-09-29 23:59:57,459 Business Factory.py-create() -270 [INFO] [1000108695] [Obtain User Profile Interf ...

Posted on Thu, 20 Dec 2018 09:36:05 -0800 by pcbytes

LeetCode3—Longest Substring Without Repeating Characters

The time complexity analysis of each algorithm in this type of blog is deduced by the blogger himself. This type of blog is also a summary of the blogger himself who brushes LeetCode. Therefore, there may be many errors in this type of blog. You are very welcome to comment below the blog. Please don't hesitate to comment. I. Problems Inp ...

Posted on Thu, 20 Dec 2018 06:03:04 -0800 by PrivatePile