前两天在服务器上安装 gevent 时出现了 gevent/gevent.core.c:1: error: CPU you selected does not support x86-64 instruction set 错误：

$ pip install gevent
Downloading/unpacking gevent
  Running setup.py egg_info for package gevent
    ....

    building 'gevent.core' extension
    gcc -pthread -DNDEBUG -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param ...

看一下下面三个例句就知道它们之间的区别了：

• There are three books on my table, One is here. Where are other books?
• There are three books on my table, One is here. Where are the others?
• There are three books on my table, Two is here. Where are another?

参考资料

• What's the difference between OTHER, OTHERS ...

译自：Cyanide & Happiness #3508 - Explosm.net

percona-toolkit 是一组高级命令行工具的集合， 用来执行各种复杂和麻烦的 MySQL 操作。

下面记录一下在 CentOS 下如何通过 rpm 安装 percona-toolkit:

1. 安装依赖
   yum install perl perl-IO-Socket-SSL perl-Time-HiRes

2. 下载 rpm 包
   wget percona.com/get/percona-toolkit.rpm

3. 安装 rpm 包
   rpm -ivh percona-toolkit-*.rpm

---EOF---

默认情况下上传的文件都是按原始编码进行保存的，用户上传什么编码的文件就保存什么编码的文件。

下面将举例说明如何通过自定义 Model Field 的方式将文件的编码改为 UTF-8。

假设有个文件: app/fields.py

import chardet
from django.db import models
from south.modelsinspector import add_introspection_rules

class UTF8TextFileField(models.FileField):
    """上传的文本文件将按 utf8 编码保存"""

    def clean(self, *args, **kwargs):
        uploaded_file = super(UTF8TextFileField, self).clean(*args, **kwargs)
        content_raw = uploaded_file.file.read()
        # 猜测原始文件编码
        encoding = chardet.detect ...