Python - Somthing similar to curry

Currying is a pretty neat idea. However python has its own partial in functools module.

So, left with nothing better to do, I had an idea of a function that waits till it has been called with the required number of arguments to return the result. That is, the arguments from the previous calls should be saved somewhere and used later.

So, here is the result almost_curry!


class almost_curry():
    def __init__(self,func):
        import inspect as insp
        self.func = func
        self.argsInFunc = insp.getargspec(func)[0]
        self.argsReq = len(self.argsInFunc)
        self.args = []
        self.kwargs = {}
   
    def __call__(self,*args,**kwargs):
        if args:
            self.args.extend(args)
            if len(self.args) == self.argsReq:
                targs = list(self.args)
                self.args = []
                return self.func(*targs)
               
        if kwargs:
            self.kwargs.update(kwargs)
            if len(self.kwargs) == self.argsReq:
                tkwargs = self.kwargs.copy()
                self.kwargs = {}
                return self.func(**tkwargs)

If we have a normal function, say sumxy,


def sumxy(x,y):
    return x+y

Now, we can do something like,
csumxy = almost_curry(sumxy)

If we call the our csumxy (its an object, not a function, but, functions are objects, oh I am getting loopy, never mind...)

csumxy(4) #just a normal call
csumxy(5) #target function has got the required number or args, so
9               # it has output the result! yay!

Takeaway: I found one use for the inspect module in python. Pulling this off without getargspec() in inspect would have required some other kind of hackery. If you have any suggestions please comment.

Google Code Jam - C++ base code

The qualification round is over! I found myself checking other people's code and I decided for the next rounds I'd need some common code to cut short the development time. There is no point in keeping this a secret, because, anyone can read other people's code and *a lot of far better, and really good code* are there if you check the code of the top 20 or so.

I plan to stick with python, however if speed of execution becomes very crucial, this will be my plan B (my plan A - using pypy ;) ).

I am treating each test case as a separate object. And since there is usually no common data  shared between  test cases, they can and should be parallelized. Pthreads are doing the job well enough, though I will try to check something with OpenMP's #pragma directive.

Note that while using pthreads and treating each test case as completely different gives us some gain, memoizing becomes a little bit more painful.

I also couldn't resist the urge to implement an ugly forAll kind of function. The doWork() is just something to test the performance gain, run this using perf in linux... and read the code and do comment if you have any suggestion, or I'll simply hunt your code down and read and learn from it ;)

#include < iostream >
#include < vector >
#include < pthread.h >

using namespace std;

class TestCase{

    private:
        int begin,end,result;

    public:
        TestCase(){begin = end = result = 0;}
        TestCase(int x, int y):begin(x),end(y){}
        void doWork();
        friend ostream & operator < < (ostream & out1,TestCase &t1);
        friend istream & operator >> (istream & in1,TestCase &t1);
};

void TestCase::doWork(){
    for(int i = 0; i < begin; i++){
        for(int j = 0; j < end*10;j++){
            for(int k = 0; k < begin; k++){
                result += 1;
            }
        }
    }
}

ostream & operator << (ostream & out1,TestCase &t1){
    out1&lt&ltt1.result;
    return out1;
}

istream & operator >> (istream & in1,TestCase &t1){
    in1 >> t1.begin &gt&gt t1.end;
    return in1;
}


inline void forAllTestCases(const int &num_testcases, vector<TestCase *> &tarr, void (*func)(TestCase * tptr)){
    int i = 0;
    while(num_testcases - i){
        func(tarr[i++]);
    }
}

void try1(TestCase * tptr){
    tptr-&gtdoWork();
}

void *doWork(void *threadArg){
    TestCase *tmp;
    tmp = reinterpret_cast<TestCase *>(threadArg);
    tmp->doWork();
}

int main(){
    int num_testcases,i;
    vector<TestCase *> tarr;
    cin>>num_testcases;

//read the input - I usually redirect the stdin
    TestCase *tptr;
    for(i=0;i<num_testcases;i++){
        tptr = new TestCase;
        cin >> *tptr;
        tarr.push_back(tptr);
    }

    vector<pthread_t> mythreads(100);
    pthread_attr_t attr;
    pthread_attr_init(&attr);
    pthread_attr_setdetachstate(&attr,PTHREAD_CREATE_JOINABLE);
    void *status;
    int rc;

   
    for(i=0;i<num_testcases;i++)
    {
        rc = pthread_create(&mythreads[i],&attr,doWork, (void *) tarr[i]);
    }

    pthread_attr_destroy(&attr);

    //forAllTestCases(num_testcases,tarr,&try1);

//print the output
    for(i = 0; i < num_testcases; i++){
        rc = pthread_join(mythreads[i],&status);
        cout<<*tarr[i]<<endl;
    }

   
}

Changing Password In BOSS Linux (Tamil Nadu Laptops)

Here is how you can change your password in BOSS Linux. The procedure is common for all GNOME 2.x Linux operating systems, but recently the BOSS Helpline is being flooded with calls from students who have received free laptops from the Tamil Nadu Government, so the support guys asked us to help them out, and so I want to be a little Google search friendly. I assume people will search something similar to Tamil Nadu Government laptop password change, or BOSS password change, or BOSS authorization code ???

If you received the laptop as part of the Tamil Nadu Gov scheme, there will be two default passwords. One is "boss" - the normal user password and the other is "root" - the administrative password.

• When you login, for example, you'll have to enter boss as password. 
• When you click on the Windows drive in linux and it asks for a password, you'll have to enter root.

To change the user password (first one)

In your desktop you should be seeing Applications, Places, System in the bottom. Click on System -> Administration -> Users and Groups.

You'll see something similar this,

Click on the change and give whatever password you want.

To change the admin password (second one)

Go to Applications -> Accessories -> Terminal

Type sudo -i and press the Enter key.

If it asks for a password, enter your first password.

If it is successful, you'll find the wordings change from boss@boss to root@boss

Now, type passwd

Enter the new password.

The system will not accept weak passwords, however if you want to make life simpler at your own peril, type pam-auth-update --remove passwdqc

After you've given that the system will not bother you when you enter weak passwords.

If you are still not sure, call 1800 4250 455