小编Ram*_*amy的帖子

最终更新:

我忘记了执行initdb命令.

</ FINAL UPDATE>

通过运行此命令

ps auxwww | grep postgres

我看到postgres没有运行

> ps auxwww | grep postgres
remcat          1789   0.0  0.0  2434892    480 s000  R+   11:28PM   0:00.00 grep postgres

这提出了一个问题:如何启动postgresql服务器？

更新:

>pg_ctl -D /usr/local/var/postgres -l /usr/local/var/postgres/server.log start
server starting
sh: /usr/local/var/postgres/server.log: No such file or directory

更新2:

触摸不成功所以我这样做了:

> mkdir /usr/local/var/postgres
> vi /usr/local/var/postgres/server.log
> ls /usr/local/var/postgres/          
server.log

但是当我尝试启动rails服务器时,我仍然看到:

Is the server running on host "localhost" and accepting
TCP/IP connections on port 5432?

更新3:

> pg_ctl -D …

为什么我得到这个例外？

package com.domain.idea;

import javax.persistence.CascadeType;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.JoinColumn;
import javax.persistence.OneToOne;
import javax.persistence.Table;

import org.hibernate.annotations.AccessType;

/**
 * object model for the view [InvestmentReturn].[vMAE_MFE]
 */
@Entity
@Table(name="vMAE_MFE", schema="InvestmentReturn")
@AccessType("field")
public class MAE_MFEView
{
    /**
     * trade property is a SuggestdTradeRecommendation object
     */
    @OneToOne(fetch = FetchType.LAZY , cascade = { CascadeType.PERSIST })
    @JoinColumn(name = "suggestedTradeRecommendationID")
    private SuggestedTradeRecommendation trade;

    /**
     * Most Adeverse Excursion value
     */
    private int MAE;

    public int getMAE()
    {
        return MAE;
    }

    /**
     * Most Favorable Excursion …

这个问题可能看起来像是一个副本:如何在我的Mac上卸载postgresql(运行Snow Leopard)但是,有两个主要的区别.我正在运行Lion,我正在尝试卸载PostgreSQL 9.0.4.我查看了最后一个问题及其引用的链接,但是当我运行此命令时,我没有找到名为"uninstall-postgresql"的文件:

sudo find / -name "*uninstall-*"  

所以,我认为这意味着9.0.4的卸载过程与8.x的卸载过程不同.

我在不同的地方看到了几个描述手动卸载方法的帖子,但同样地,我的机器上没有引用的一些目录/文件.

我们将非常感谢您提供的任何帮助或指导.

仅供参考,这是用于从雪豹中卸载postgres的另一张海报的链接.当我试图逐步执行这些命令时,大多数命令都被"未找到命令"的变体所阻塞.

更新:

除此之外brew uninstall postgres,我应该手动删除以下任何文件/目录吗？请记住,我想完全擦除平板,没有数据文件/数据库表或任何东西.

> sudo find / -name "*postgres*"             
find: /dev/fd/3: Not a directory
find: /dev/fd/4: Not a directory
/Library/Ruby/Gems/1.8/doc/activerecord-3.1.1/rdoc/lib/active_record/connection_adapters/postgresql_adapter_rb.html
/Library/Ruby/Gems/1.8/doc/activerecord-3.1.1/ri/ActiveRecord/ConnectionAdapters/PostgreSQLAdapter/postgresql_version-i.ri
/Library/Ruby/Gems/1.8/doc/arel-2.2.1/rdoc/lib/arel/visitors/postgresql_rb.html
/Library/Ruby/Gems/1.8/gems/activerecord-3.1.1/lib/active_record/connection_adapters/postgresql_adapter.rb
/Library/Ruby/Gems/1.8/gems/arel-2.2.1/lib/arel/visitors/postgresql.rb
/Library/Ruby/Gems/1.8/gems/arel-2.2.1/test/visitors/test_postgres.rb
/Library/Ruby/Gems/1.8/gems/railties-3.1.1/lib/rails/generators/rails/app/templates/config/databases/jdbcpostgresql.yml
/Library/Ruby/Gems/1.8/gems/railties-3.1.1/lib/rails/generators/rails/app/templates/config/databases/postgresql.yml
/Library/WebServer/Documents/postgresql
/Library/WebServer/Documents/postgresql/html/app-postgres.html
/Library/WebServer/Documents/postgresql/html/postgres-user.html
/private/etc/apache2/users/postgres.conf
/private/var/db/dslocal/nodes/Default/groups/_postgres.plist
/private/var/db/dslocal/nodes/Default/sharepoints/postgres's Public Folder.plist
/private/var/db/dslocal/nodes/Default/users/_postgres.plist
/private/var/db/dslocal/nodes/Default/users/postgres.plist
/System/Library/DirectoryServices/DefaultLocalDB/Default/groups/_postgres.plist
/System/Library/DirectoryServices/DefaultLocalDB/Default/users/_postgres.plist
/Users/postgres
/Users/remcat/dev/working/startwire/vendor/plugins/foreign_keys/lib/foreign_keys/postgresql_adapter.rb
/Users/remcat/Library/Application Support/CrashReporter/postgres_DCCEF98F-4602-5FF7-964F-5E717AC007B4.plist
/Users/remcat/Library/Caches/Homebrew/postgresql-9.0.4.tar.bz2
/Users/remcat/Library/Caches/Metadata/Safari/History/http:%2F%2Fwww.postgresql.org%2Fdocs%2Fcurrent%2Fstatic%2Findex.html.webhistory
/Users/remcat/Library/Logs/CrashReporter/postgres_2011-11-06-194716_Ramys-MacBook-Pro.crash
/Users/remcat/Library/Logs/CrashReporter/postgres_2011-11-06-194742_Ramys-MacBook-Pro.crash
/Users/remcat/Library/Logs/CrashReporter/postgres_2011-11-06-194757_Ramys-MacBook-Pro.crash
/Users/remcat/Library/Logs/CrashReporter/postgres_2011-11-06-194958_Ramys-MacBook-Pro.crash
/Users/remcat/Library/Logs/CrashReporter/postgres_2011-11-06-203352_Ramys-MacBook-Pro.crash
/Users/remcat/Library/Logs/CrashReporter/postgres_2011-11-06-203359_Ramys-MacBook-Pro.crash
/Users/remcat/Library/Logs/DiagnosticReports/.postgres_2011-11-06-194716_Ramys-MacBook-Pro.crash.plist
/Users/remcat/Library/Logs/DiagnosticReports/.postgres_2011-11-06-194742_Ramys-MacBook-Pro.crash.plist
/Users/remcat/Library/Logs/DiagnosticReports/.postgres_2011-11-06-194757_Ramys-MacBook-Pro.crash.plist
/Users/remcat/Library/Logs/DiagnosticReports/.postgres_2011-11-06-194958_Ramys-MacBook-Pro.crash.plist
/Users/remcat/Library/Logs/DiagnosticReports/.postgres_2011-11-06-203352_Ramys-MacBook-Pro.crash.plist
/Users/remcat/Library/Logs/DiagnosticReports/.postgres_2011-11-06-203359_Ramys-MacBook-Pro.crash.plist
/Users/remcat/Library/Logs/DiagnosticReports/postgres_2011-11-06-194716_Ramys-MacBook-Pro.crash
/Users/remcat/Library/Logs/DiagnosticReports/postgres_2011-11-06-194742_Ramys-MacBook-Pro.crash
/Users/remcat/Library/Logs/DiagnosticReports/postgres_2011-11-06-194757_Ramys-MacBook-Pro.crash
/Users/remcat/Library/Logs/DiagnosticReports/postgres_2011-11-06-194958_Ramys-MacBook-Pro.crash
/Users/remcat/Library/Logs/DiagnosticReports/postgres_2011-11-06-203352_Ramys-MacBook-Pro.crash
/Users/remcat/Library/Logs/DiagnosticReports/postgres_2011-11-06-203359_Ramys-MacBook-Pro.crash …

我正在使用itertools.chain以这种方式"压扁"列表列表:

uniqueCrossTabs = list(itertools.chain(*uniqueCrossTabs))

这有什么不同于说:

uniqueCrossTabs = list(itertools.chain(uniqueCrossTabs))

如何判断我的Postgresql服务器是否正在运行？

我收到这条消息:

[~/dev/working/sw] sudo bundle exec rake db:migrate 
rake aborted!
could not connect to server: Connection refused
    Is the server running on host "localhost" and accepting
    TCP/IP connections on port 5432?

更新:

> which postgres
/usr/local/bin/postgres
> pg_ctl -D /usr/local/bin/postgres -l /usr/local/bin/postgres/server.log start
pg_ctl: could not open PID file "/usr/local/bin/postgres/postmaster.pid": Not a directory

更新2:

>pg_ctl -D /usr/local/var/postgres -l /usr/local/var/postgres/server.log start
server starting
sh: /usr/local/var/postgres/server.log: No such file or directory

如果我有一个列表理解(例如)像这样:

['' for x in myList]

有效地为列表中的每个元素创建一个具有空字符串的新列表,我从不使用x.有没有更简洁的方法来写这个,所以我不必声明未使用的x变量？

我做了一个小帮手功能:

import zipfile

def main(archive_list=[],zfilename='default.zip'):
    print zfilename
    zout = zipfile.ZipFile(zfilename, "w")
    for fname in archive_list:
        print "writing: ", fname
        zout.write(fname)
    zout.close()

if __name__ == '__main__':
    main()  

问题是我的所有文件都没有被压缩!这些文件的大小相同,实际上只是扩展名被更改为".zip"(在本例中为".xls").

我在winXP sp2上运行python 2.5.

如何将我的工作和更改从master分支移动到新创建的分支,并在移动后保持主分支完整？

我正在教一个关于面向对象编程的python类,当我正在研究如何解释类​​时,我看到了一个空的类定义:

class Employee:
    pass

然后,该示例继续为此类的对象定义名称和其他属性:

john = Employee()
john.full_name = "john doe"

有趣!

我想知道是否有一种方法可以为这样的类的实例动态定义函数？就像是:

john.greet() = print 'hello world!'

这在我的python解释器中不起作用但是有另一种方法吗？

只需从本文中了解语句即可

问题是,我可以通过论证__enter__吗？

我有这样的代码:

class clippy_runner:
    def __enter__(self):
        self.engine = ExcelConnection(filename = "clippytest\Test.xlsx")
        self.db = SQLConnection(param_dict = DATASOURCES[STAGE_RELATIONAL])

        self.engine.connect()
        self.db.connect()

        return self

我想将filename和param_dict作为参数传递给__enter__.那可能吗？