How to deal with difficult people

Have you ever wondered why some people are difficult to work with?
Individuals behave in a difficult manner because they have learned that doing so keeps others off balance and incapable of effective action. Worst of all, they appear immune to all the usual methods of communication and persuasion designed to convince or help them change their ways
How to Cope
Avoid these “don'ts” when dealing with difficult people:
Don't take difficult people's behaviour personally. Their troublesome behaviour is habitual and affects most people with whom they come in contact.
Don't fight back or try to beat them at their own games. They have been practicing their skills for a lifetime, and you're an amateur.
Don't try to appease them. Difficult people have an insatiable appetite for more.
Don't try to change them. You can only change your responses to their behaviour.
Here's how you can cope effectively with following common types of difficult people.
The Complainer
There's always one person in a office who can never find anything about which to be happy. If he's not complaining about his health or family, he's complaining about his job, the company, or even his superior. Of course, some of his complaints may be legitimate, but the incessant whining is getting on your nerves. Generally, the complainer isn't looking for advice so offering it probably won't do any good. Change the subject whenever the bellyaching begins. Your colleague should get the hint after you do this repeatedly.
The Delegator
In almost every workplace you'll find someone who wants to share his work with his colleagues. I am not talking about those who have a legitimate reason to delegate work to others .I am speaking of those who either can't do all the work, they have been given or don't want to do it.. Tell your co worker you have your own work with which  you have to deal and you have no time to engage with his assignment.
The Credit Grabber
The credit grabber does not acknowledge any help he receives from others. he accepts all the praise for a successfully completed assignment without mentioning that he didn't do it alone. The first time this happens, consider it a mistake. Mention it to your colleague and ask him to let others know about your participation. If he doesn't, or if this happens again, make sure you let others know about the role you played in getting that project done. Then, unless you are mandated to work with this person, refuse to help out again.