I have been writing Python crawlers and python gadgets for more than two years as an amateur. I recommend some videos and articles that I think are good for learning

directory

  • Expansion pack
  • The crawler article
  • Data Analysis

Expansion pack

Python3 beginner tutorial video Teaching Chinese university MOOC, Personally, I prefer Mr. Song tian’s courses. There are many courses involving Python programming, Python web crawler and information extraction, Python data analysis and presentation, and THREE-DIMENSIONAL visualization of Python scientific calculation, etc. It can be said that all of Mr. Song Tian’s courses are available. Secondly, the video is recommended to don’t bother Python, which has the article introduction and video introduction. Others prefer the article introduction, which is faster and saves time

The crawler article

Introduce the third-party libraries involved in crawlers and their related documentation

  1. urllib3
  2. Urllib3 document
  3. Requests the document
  4. Beautiful Soup
  5. Beautiful Soup Chinese Version
  6. Regular expressions
  7. scrapy
  8. Scrapy document
  9. CSS selector syntax
  10. Re regular expression syntax
  11. Xpath syntax
  12. PyMySQL
  13. PyMySQL document

Data Analysis

Introduction to third-party libraries for data analysis

  1. Blaze
  2. Open Mining
  3. Orange
  4. Pandas
  5. Optimus
  6. NumPy

Attached is the total value of the third-party libraries for different uses of Python on Github

CSS selector syntax

Expression description * Select all nodes#container Select the node whose ID is ContainerContainer Select all class nodes that contain container li a select all nodes a under li ul + p Select the first P element div after ulSelect the first ul child of the div whose ID is containerUl ~ p Selects all p elements adjacent to ul. A [title] Selects all elements a that have the title attribute. A [href="http://baidu.com"] select all elements a[href*= whose href attribute is http://baidu.com"baidu"] Select all the a element a[href^= that contains the HREF attribute of Baidu"http"[href$=] select all a elements whose href values start with HTTP".jpg"Select all a elements whose href values end in.jpgtype< div:not();Select all div attributes whose ID is not ContainerLi: the NTH - child element (3) to select the third li tr: NTH child (2 n) - the first an even number of tr/CSS video introduction (http://www.w3school.com.cn/css/css_selector_type.asp)Copy the code

Re regular expression syntax

Character match. Any character (except \n) [...] Character set \d/\ d digit/non-digit \s/\ s blank/non-blank \w/\ w word characters [a-za-z0-9]/ non-word characters * 0 or unlimited times + 1 or unlimited times of the previous character? 0 or 1 {m}/{m,n} m or n *? / +? /?? Not greed (characters) as little as possible ^ string beginning at $string at the end of the A / \ \ Z specified string must appear at the beginning/end | match around an arbitrary expression (ab) expression in the brackets as A grouping \ < number > reference Numbers for num group match to string (? P<name>) to group an alias (? P=name) references the group alias name to the matching string [\u4E00-\u9FA5] a Chinese characterCopy the code

Xpath syntax

Expression description article selects all the children of the article element /article selects all the a elements that are children of the article element //div selects all the div children (no matter where in the document) Article //div selects all div elements that are descendants of the input article element, //@class selects all attributes named class /article/div[1] Selects the first div element that is a child of article/ article/div[last()] (article/div[last()-1] (article/div[last()-1]) (article/div[@lang]) (article/div[@lang=))) (article/div[@lang=))) (article/div[@lang=))'eng] select all lang attribute selection for eng div elements/div / * belongs to div elements all the elements of all child nodes selection / / * / / div [@ *] select all take properties of the title element / / div/a | / / div/p select all div elements of a and p elements / / span | / selection/ul document span and ul element in the article/div/p | / / span select all belong to the div elements of the article element of p elements and all span element in the documentCopy the code