便签

  • 2017-10-30
    • Java
      • Redirection and piping.

      • 对于自己创建的每一个类，都考虑置入一个main()，其中包含了用于测试那个类的代码。为使用一个项目中的类，我们没必要删除测试代码。若进行了任何形式的改动，可方便地返回测试。这些代码也可作为如何使用类的一个示例使用。

  • 2017-10-30
    • Java
      • Printing strings to the terminal window.
      • Converting strings to primitive types.
      • Mathematical functions.
  • 2017-10-01
    • Python
      替学委写的自动纠正文件名小程序，被学委嫌弃了。
      1
      2
      3
      4
      5
      6
      7
      8
      9
      10
      11
      12
      13
      14
      15
      16
      17
      18
      19
      20
      21
      22
      23
      24
      25
      26
      27
      28
      29
      30
      31
      32
      33
      34
      35
      36
      37
      38
      39
      40
      41
      42
      43
      44
      # -*- coding:utf-8 -*-
      """
      将此源码与 name.txt 存放在同一目录下
      双击运行 prog.py，重命名文件将生成于 new 文件夹中
      """
      import os
      import shutil
      def getMap():
      	lst = []
      	with open("./name.txt", 'r', encoding="utf-8") as f:
      		for line in f:
      			lst.append((line.split("\t")[0], line.split("\t")[2]))
      		f.close()
      	return lst
      def changeName(folder, cap):
      	oldDir = folder
      	newDir = os.path.join(oldDir, "new")
      	if (not os.path.isdir(newDir)):
      		os.mkdir(newDir)
      	nameToId = getMap()
      	for oldFile in os.listdir(oldDir):
      		flag = False
      		for name, no in nameToId:
      			if (oldFile.find(name) != -1):
      				newFile = "计科一班-" + name + "-" + cap + "-" + no + "." + oldFile.split(".")[-1]
      				shutil.copyfile(os.path.join(oldDir, oldFile), os.path.join(newDir, newFile))
      				flag = True
      				print("{:30}\t{}  {}".format(oldFile, " 已成功重命名为 ", newFile))
      				break
      		if (flag == False):
      			if (oldFile != "new"):
      				print("{:30}\t{}".format(oldFile, " 重命名失败！"))
      def main():
      	folder = input("作业文件夹：")
      	cap = input("请输入章节：")
      	changeName(folder, cap)
      	input("---- 按 Enter 结束程序 ----")
      	
      main()

  • 2017-09-16

    • C

      • 1
        2
        while((ch = getchar()) != EOF)
        	putchar(ch);

        结束输入需要手动模拟EOF，如Ctrl+Z

      • 1
        echo_eof < words

        把stdin重定位到words文件。

        1
        echo_eof > mywords

        把stdout重定位到mywords文件。

        注：重定位是一个命令行概念。

      • 向函数传入数组，如果对数组并不进行修改操作，建议形式参数使用const。

        1
        2
        3
        4
        int sum(const int arr[], int n)
        {
        	// something
        }

      • 声明字符串时最好用char str[]，这样str就有了const的感觉。

    • Python

      • 爬取股票信息，包含进度条（进度条在cmd中才能正常显示）
        1
        2
        3
        4
        5
        6
        7
        8
        9
        10
        11
        12
        13
        14
        15
        16
        17
        18
        19
        20
        21
        22
        23
        24
        25
        26
        27
        28
        29
        30
        31
        32
        33
        34
        35
        36
        37
        38
        39
        40
        41
        42
        43
        44
        45
        46
        47
        48
        49
        50
        51
        52
        53
        54
        55
        56
        57
        58
        59
        60
        61
        62
        63
        64
        65
        66
        67
        68
        import requests
        from bs4 import BeautifulSoup
        import traceback
        import re
        def getHTMLText(url, code="utf-8"):
        	try:
        		r = requests.get(url,timeout = 30)
        		r.raise_for_status()
        		r.encoding = code
        		return r.text
        	except:
        		print("404")
        		return ""
        def getStockList(lst, stockURL):
        	html = getHTMLText(stockURL, "GB2312")
        	soup = BeautifulSoup(html, "html.parser")
        	a = soup.find_all('a')
        	for i in a:
        		try:
        			href = i.attrs["href"]
        			lst.append(re.findall(r"[s][hz]\d{6}", href)[0])
        		except:
        			continue
        def getStockInfo(lst, stockURL, fpath):
        	count = 0
        	for stock in lst:
        		url = stockURL + stock + ".html"
        		html = getHTMLText(url)
        		try:
        			if html == "":
        				continue
        			infoDict = {}
        			soup = BeautifulSoup(html, "html.parser")
        			stockInfo = soup.find("div", attrs={"class":"stock-bets"})
        			name = stockInfo.find_all(attrs={"class":"bets-name"})[0]
        			infoDict.update({"股票名称":name.text.split()[0]})
        			keyList = stockInfo.find_all("dt")
        			valueList = stockInfo.find_all("dd")
        			for i in range(len(keyList)):
        				key = keyList[i].text
        				val = valueList[i].text
        				infoDict[key] = val
        			with open(fpath, 'a', encoding="utf-8") as f:
        				f.write(str(infoDict) + '\n')
        				count = count + 1
        				print("\r当前进度：{:.2f}%".format(count*100/len(lst)),end='')
        		except:
        			count = count + 1
        			print("\r当前进度：{:.2f}%".format(count*100/len(lst)),end='')
        			continue
        		
        def main():
        	stock_list_url = "http://quote.eastmoney.com/stocklist.html"
        	stock_info_url = "https://gupiao.baidu.com/stock/"
        	output_file = "G://BaiduStockInfo.txt"
        	slist = []
        	getStockList(slist, stock_list_url)
        	getStockInfo(slist, stock_info_url, output_file)
        main()

  • 2017-09-15

    • C

      • 匿名数组

        1
        2
        int * pt1;
        pt1 = (int [2]){10, 20};
        1
        2
        3
        4
        5
        int sum(const int arr[], int n);
        ...
        ...
        int total;
        total = sum((int []){4, 4, 4, 5, 5, 5}, 6);
  • 2017-09-09
    • JavaScript
      atob(),btoa() - 两个函数，作用：不会被一下子看穿秘密
  • 2017-09-08
    • Python
      淘宝比价爬虫
      1
      2
      3
      4
      5
      6
      7
      8
      9
      10
      11
      12
      13
      14
      15
      16
      17
      18
      19
      20
      21
      22
      23
      24
      25
      26
      27
      28
      29
      30
      31
      32
      33
      34
      35
      36
      37
      38
      39
      40
      41
      42
      43
      44
      45
      46
      47
      48
      49
      50
      51
      52
      import requests
      import re
      import os
      def getHTMLTest(url):
      	try:
      		r = requests.get(url,timeout = 30)
      		r.raise_for_status()
      		r.encoding = r.apparent_encoding
      		return r.text
      	except:
      		return ""
      def parsePage(ilt, html):
      	try:
      		plt = re.findall(r'\"view_price\"\:\"[\d\.]*\"', html)
      		tlt = re.findall(r'\"raw_title\"\:\".*?\"', html)
      		for i in range(len(plt)):
      			price = eval(plt[i].split(':')[1])
      			title = eval(tlt[i].split(':')[1])
      			ilt.append([price, title])
      	except:
      		print("")
      def writeGoodsList(ilt):
      	file = "淘宝机械键盘比价.txt"
      	with open(file, 'w') as f:
      		tplt = "{:4}\t{:8}\t{:16}\n"
      		f.write(tplt.format("序号", "价格", "商品名称"))
      		count = 0
      		for g in ilt:
      			count = count + 1
      			f.write(tplt.format(count, g[0], g[1]))
      		f.close()
      		print("文件保存成功")
      		
      def main():
      	goods = "机械键盘"
      	depth = 5
      	start_url = "https://s.taobao.com/search?q=" + goods
      	infoList = []
      	for i in range(depth):
      		try:
      			url = start_url + "&s=" + str(44 * i)
      			html = getHTMLTest(url)
      			parsePage(infoList, html)
      		except:
      			continue
      	writeGoodsList(infoList)
      main()
  • 2017-09-05
    • 汇编
      x86-64中，移位操作对w位长的数据值进行操作，移位量是由%cl寄存器的低m位决定的，这里2^m=w。高位会被忽略。所以，例如当寄存器%cl的十六进制值为0xFF时，指令salb会移7位，salw会移15位，sall会移31位，而salq会移63位。
  • 2017-09-02
    • Python
      帮Karen爬植物志
      1
      2
      3
      4
      5
      6
      7
      8
      9
      10
      11
      12
      13
      14
      15
      16
      17
      18
      19
      20
      21
      22
      23
      24
      25
      26
      27
      28
      29
      30
      31
      32
      33
      34
      35
      36
      37
      38
      39
      40
      41
      42
      43
      44
      45
      46
      47
      48
      import requests
      from bs4 import BeautifulSoup
      import codecs
      def getHTMLText(url):
      	try:
      		r = requests.get(url, timeout=30)
      		r.raise_for_status()
      		r.encoding = "gbk"
      		return r.text
      	except:
      		return "404"
       
      def fillPlantList(html):
      	soup = BeautifulSoup(html, "html.parser")
      	plant_name_list = []
      	for tr in soup.find_all("tr", attrs={"bgcolor": "#C1CDDB"}):
      		tds = tr("td")
      		plant_name_list.append(tds[1].string)
      	next_page = None
      	
      	for a in soup.find_all("a", attrs={"class": "bt"}):
      		if (a.text == "下一页"):
      			next_page = a
      	if next_page:
      		return plant_name_list, "http://gjk.scib.ac.cn/gdzwz/" + next_page["href"]
      	else:
      		return plant_name_list, None
      	 
      def main():
      	url = "http://gjk.scib.ac.cn/gdzwz/result.asp"
      	with codecs.open("plant", "wb", encoding="gbk") as fp:
      		while url:
      			html = getHTMLText(url)
      			plant, url = fillPlantList(html)
      			for plant_name in plant:
      				if (plant_name):
      					fp.write(plant_name + '\n')
      				else:
      					fp.write('\n')
      if __name__ == "__main__":
      	main()
  • 2017-09-01
    • Python
      • 获取大学排名
        1
        2
        3
        4
        5
        6
        7
        8
        9
        10
        11
        12
        13
        14
        15
        16
        17
        18
        19
        20
        21
        22
        23
        24
        25
        26
        27
        28
        29
        30
        31
        32
        33
        34
        35
        36
        37
        38
        #coding=utf-8
        import requests
        from bs4 import BeautifulSoup
        import bs4
         
        def getHTMLText(url):
        	try:
        		r = requests.get(url, timeout=30)
        		r.raise_for_status()
        		r.encoding = r.apparent_encoding
        		return r.text
        	except:
        		return ""
         
        def fillUnivList(ulist, html):
        	soup = BeautifulSoup(html, "html.parser")
        	for tr in soup.find('tbody').children:
        		if isinstance(tr, bs4.element.Tag):
        			tds = tr('td')
        			ulist.append([tds[0].string, tds[1].string, tds[3].string])
         
        def printUnivList(ulist, num):
        	tplt = "{0:^10}\t{1:{3}^10}\t{2:^10}"
        	print(tplt.format("排名","学校名称","总分",chr(12288)))
        	for i in range(num):
        		u=ulist[i]
        		print(tplt.format(u[0],u[1],u[2],chr(12288)))
        	 
        def main():
        	uinfo = []
        	url = 'http://www.zuihaodaxue.cn/zuihaodaxuepaiming2016.html'
        	html = getHTMLText(url)
        	fillUnivList(uinfo, html)
        	printUnivList(uinfo, 100)
        if __name__ == "__main__":
        	main()

  • 2017-08-31

    • Python
      • 获取图片
        1
        2
        3
        4
        5
        6
        7
        8
        9
        10
        11
        12
        13
        14
        15
        16
        17
        18
        19
        import requests
        import os
        url = "http://image.nationalgeographic.com.cn/2017/0830/20170830031247622.jpg"
        root = "F://pics//"
        path = root + url.split('/')[-1]
        try:
        	if not os.path.exists(root):
        		os.mkdir(root)
        	if not os.path.exists(path):
        		r = requests.get(url)
        		with open(path, 'wb') as f:
        			f.write(r.content)
        			f.close()
        			print("文件保存成功")
        	else:
        		print("文件已存在")
        except:
        	print("爬取失败")

  • JavaScript

    • 屏蔽alert()方法

      1
      2
      3
      4
      window.alert = function (a) {
      	console.log(a)
      	return 1
      }

    • 函数别名

      1
      var log = console.log.bind(console)

    • 监听键盘按键

      1
      2
      3
      4
      5
      window.addEventListener('keydown', function(event) {
      	var k = event.key
      	
      	if (k === '...') {...}
      })
  • 2017-08-30
    • C
      • 如果在格式字符串中%c之前有一个空格, 那么scanf()会跳到第一个非空白字符处. 即: scanf("% c", &ch)会读取遇到的第一个非空白字符.
      • 本人保证输入数据的可靠性的方法，以读取long数据为例
        1
        2
        3
        4
        5
        6
        7
         void getlong(long *num)
        {
        	while (scanf("%ld", num) != 1)
        		getchar();
        	while (getchar() != '\n')
        		;
        }  // 事后再回显一下
  • 2017-08-28
    • JavaScript
      • 已绑定到函数参数的值不变
      • JSON.stringify(something)，将something这个对象序列化成JSON格式，stringify哈哈哈哈哈哈好好笑