eval

While [] + [] is an empty string, [] + {} is "[object Object]" , and {} + [] is 0 . Why is {} + {} NaN? > {} + {} NaN My question isn't why ({} + {}).toString() is "[object Object][object Object]" while NaN.toString() is "NaN" , this part has an answer here already . My question is why does this happen only on the client side? On the server side ( Node.js ) {} + {} is "[object Object][object Object]" . > {} + {} '[object Object][object Object]' Summarizing : On the client side: [] + [] // Returns "" [] + {} // Returns "[object Object]" {} + [] // Returns 0 {} + {} // Returns NaN NaN.toString()

I have a series of the form: s 0 [133, 115, 3, 1] 1 [114, 115, 2, 3] 2 [51, 59, 1, 1] dtype: object Note that its elements are strings : s[0] '[133, 115, 3, 1]' I'm trying to use pd.eval to parse this string into a column of lists. This works for this sample data. pd.eval(s) array([[133, 115, 3, 1], [114, 115, 2, 3], [51, 59, 1, 1]], dtype=object) However, on much larger data (order of 10K), this fails miserably! len(s) 300000 pd.eval(s) AttributeError: 'PandasExprVisitor' object has no attribute 'visit_Ellipsis' What am I missing here? Is there something wrong with the function or my data? TL

Redis中使用Lua脚本（一） 一、简介 二、Redis中Lua的常用命令 2.1 EVAL命令 2.2 SCRIPT LOAD命令 和 EVALSHA命令 2.3 SCRIPT EXISTS 命令 2.4 SCRIPT FLUSH 命令 2.5 SCRIPT KILL 命令 三、Redis执行Lua脚本文件 3.1 编写Lua脚本文件 3.2 执行Lua脚本文件 四、实例：使用Lua控制IP访问频率 五、总结 参考资料 一、简介 Redis中为什么引入Lua脚本？ Redis是高性能的key-value内存数据库，在部分场景下，是对关系数据库的良好补充。 Redis提供了非常丰富的指令集，官网上提供了200多个命令。但是某些特定领域，需要扩充若干指令原子性执行时，仅使用原生命令便无法完成。 Redis 为这样的用户场景提供了 lua 脚本支持，用户可以向服务器发送 lua 脚本来执行自定义动作，获取脚本的响应数据。Redis 服务器会单线程原子性执行 lua 脚本，保证 lua 脚本在处理的过程中不会被任意其它请求打断。 Redis意识到上述问题后，在2.6版本推出了 lua 脚本功能，允许开发者使用Lua语言编写脚本传到Redis中执行。使用脚本的好处如下: 减少网络开销。可以将多个请求通过脚本的形式一次发送，减少网络时延。 原子操作。Redis会将整个脚本作为一个整体执行

I know this question sounds rather vague so I will make it more clear with an example: $var = 'bar'; $bar = new {$var}Class('var for __construct()'); //$bar = new barClass('var for __construct()'); This is what I want to do. How would you do it? I could off course use eval() like this: $var = 'bar'; eval('$bar = new '.$var.'Class(\'var for __construct()\');'); But I'd rather stay away from eval(). Is there any way to do this without eval()? Paul Dixon Put the classname into a variable first: $classname=$var.'Class'; $bar=new $classname("xyz"); This is often the sort of thing you'll see wrapped

shell脚本一句话查找PHP一句话木马 # find ./ -name "*.php" |xargs egrep "phpspy|c99sh|milw0rm|eval(gunerpress|eval(base64_decoolcode|spider_bc))" > /tmp/php.txt # grep -r --include=*.php '[^a-z]eval($_POST' . > /tmp/eval.txt # grep -r --include=*.php 'file_put_contents(.*$_POST[.*]);' . > /tmp/file_put_contents.txt # find ./ -name "*.php" -type f -print0 | xargs -0 egrep "(phpspy|c99sh|milw0rm|eval(gzuncompress(base64_decoolcode|eval(base64_decoolcode|spider_bc|gzinflate)" | awk -F: '{print $1}' | sort | uniq python脚本查找PHP一句话木马（注意缩进） #!/usr/bin/python # -*- coding: utf-8 -*- #blog:www.sinesafe.com import os