My first Python Script_Generate a certain type string of a certain length

[malinda2008]

To accomplish teacher Hong's homework,I wrote a piece of code this afternoon.There are no use guide or UI yet.Just look at the script and help me find defects.Or you can suggest better algorithm.Welcome!

CapLetters=['A','B','C','D','E']

SmaLetters=['a','b','c','d','e']

Numbers=['1','2','3','4','5']

Specials=['!','@','#','$','%']

Direction={'U':CapLetters,'L':SmaLetters,'N':Numbers,'S':Specials}

import random

def GenRandStr(strlen,*shortletter):

        

    BeforeSort=[]

    TypeNum=len(shortletter)

    

    if TypeNum>strlen:

        print "Wrong!String too short!"

        return ""

    else:

        for EachLetter in shortletter:

                if Direction.has_key(EachLetter):

                    ExtendList=Direction[EachLetter]

                    BeforeSort.extend(random.choice(ExtendList))

                else:

                    print "Unexpected parameters!Try again!"

                    return ""

        Joined=JoinLists(shortletter)

        for i in range(0,strlen-TypeNum):

            BeforeSort.extend(random.choice(Joined))

        random.shuffle(BeforeSort)

        JoinString=""

        return JoinString.join(BeforeSort)

def JoinLists(somelist):

    JoinedList=[]

    for Type in somelist:

        JoinedList.extend(Direction[Type])

    return JoinedList

print GenRandStr(5,"U","L","N")

#raw_input('Press enter to exit.')

[Arthur]

Excellent job, Man!!

Here is a tip for you. Next time when you paste your code in the topic, you can use the Highlight Code Syntax function to make your code more readable, just look like this.. :-)

[Chris]

You are the best I have ever seen. Excellent girl !!!

You are so intelligent,following your deep heart,and achieve it. you are my idol. 

 Just like the first strong impress you give me. when Ath said some new tech.,you always can explain it using your own logic.

I hope you can keep this enthusiasm.  keep going........

We are forever young.

2012/12/21 malinda2008 <malin...@gmail.com>

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-----  Excellent is a habit. -----

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[张明旭张]

Thanks, my mentor. Really helpful suggest.

2012/12/21 Arthur <hfan...@gmail.com>

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[张明旭张]

Thanks,Chris! You are my idol too. Next stop:a lesson of "class" and a dictionary of my own.

2012/12/21 Chris <iloo...@gmail.com>