Zhentiw - 博客园

2017年12月9日

[Python] Check for None (Null) in Python

摘要： If you’ve used other programming languages, you may have learned that an empty object is not the same as an object that does not exist. In this lesson 阅读全文

posted @ 2017-12-09 17:49 Zhentiw 阅读(1463) 评论(0) 推荐(0)

[Python] Manage Dependencies with Python Virtual Environments

摘要： Virtual Environments ensure that dependencies from one Python application don’t overwrite the dependencies of another application. In this lesson, you 阅读全文

posted @ 2017-12-09 17:41 Zhentiw 阅读(208) 评论(0) 推荐(0)

2017年12月8日

[React] Controlling Form Values with React

摘要： In this lesson we'll talk about controlling the value for inputs, textareas, and select elements. We'll see how to manage the state ourselves while st 阅读全文

posted @ 2017-12-08 20:54 Zhentiw 阅读(202) 评论(0) 推荐(0)

2017年12月7日

[React] Stop Memory Leaks with componentWillUnmount Lifecycle Method in React

摘要： In this lesson we'll take a stopwatch component we built in another lesson and identify and fix a memory leak. Tow things to notice here is that: 1. t 阅读全文

posted @ 2017-12-07 20:33 Zhentiw 阅读(714) 评论(0) 推荐(0)

[React] Validate Custom React Component Props with PropTypes

摘要： In this lesson we'll learn about how you can use the prop-types module to validate a custom React component's props. You can write you own PropTypes v 阅读全文

posted @ 2017-12-07 20:09 Zhentiw 阅读(239) 评论(0) 推荐(0)

[Python] Wikipedia Crawler

摘要： import time import urllib import bs4 import requests start_url = "https://en.wikipedia.org/wiki/Special:Random" target_url = "https://en.wikipedia.org/wiki/Philosophy" def find_first_link(url): ... 阅读全文

posted @ 2017-12-07 16:36 Zhentiw 阅读(364) 评论(0) 推荐(0)

[Python] Python list slice syntax fun

摘要： # Python's list slice syntax can be used without indices # for a few fun and useful things: # You can clear all elements from a list: >>> lst = [1, 2, 3, 4, 5] >>> del lst[:] >>> lst [] # You can r... 阅读全文

posted @ 2017-12-07 15:39 Zhentiw 阅读(246) 评论(0) 推荐(0)

[Python] Finding the most common elements in an iterable

摘要： https://docs.python.org/2/library/collections.html 阅读全文

posted @ 2017-12-07 15:20 Zhentiw 阅读(209) 评论(0) 推荐(0)

[Python] Generates permutations

摘要： >>> import itertools >>> for p in itertools.permutations('ABCD'): ... print(p) ('A', 'B', 'C', 'D') ('A', 'B', 'D', 'C') ('A', 'C', 'B', 'D') ('A', 'C', 'D 阅读全文

posted @ 2017-12-07 15:10 Zhentiw 阅读(208) 评论(0) 推荐(0)

2017年11月30日

[Javascript] Compose multiple functions for new behavior in JavaScript

摘要： In this lesson you will create a utility function that allows you to quickly compose behavior of multiple functions to create new behavior. By the end 阅读全文

posted @ 2017-11-30 17:50 Zhentiw 阅读(288) 评论(0) 推荐(0)

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