Sum elements in a row (Python/Numpy)
Question: Working on a project that gives us free reign on what to use. So I decided I'd
learn python for it.

To make this short, I want sum all the elements in a "row" of a matrix I'm
reading in.

This is what my 2D array looks like after I read in my table from my text
file.

    
    
    ['0000' '0' '0' '0' '0' '0' '0' '0' '0' '0' '0' '0' '0' '0' '1']
    ['0001' '0' '1' '0' '1' '0' '0' '0' '0' '1' '0' '0' '0' '0' '1']
    ['0010' '0' '1' '0' '1' '0' '0' '0' '0' '1' '0' '0' '0' '0' '1']
    ['0011' '0' '1' '0' '1' '0' '0' '0' '0' '1' '0' '0' '0' '0' '1']
    ['0100' '0' '0' '0' '0' '0' '1' '0' '1' '0' '0' '1' '0' '0' '1']
    ['0101' '0' '0' '1' '0' '0' '0' '1' '0' '0' '1' '0' '1' '1' '0']
    ['0110' '0' '0' '1' '0' '1' '0' '0' '0' '0' '1' '0' '1' '1' '0']
    ['0111' '0' '0' '1' '0' '0' '0' '0' '0' '0' '1' '0' '0' '1' '0']
    ['1000' '0' '0' '0' '0' '0' '1' '0' '1' '0' '0' '1' '0' '0' '1']
    ['1001' '1' '0' '0' '0' '0' '0' '1' '0' '0' '1' '0' '1' '1' '0']
    ['1010' '1' '0' '0' '0' '1' '0' '0' '0' '0' '1' '0' '1' '1' '0']
    ['1011' '1' '0' '0' '0' '0' '0' '0' '0' '0' '1' '0' '0' '1' '0']
    ['1100' '0' '0' '0' '0' '0' '1' '0' '1' '0' '0' '1' '0' '0' '1']
    ['1101' '0' '0' '0' '0' '0' '0' '1' '0' '0' '0' '0' '1' '1' '0']
    ['1110' '0' '0' '0' '0' '1' '0' '0' '0' '0' '0' '0' '1' '1' '0']
    ['1111' '0' '0' '0' '0' '0' '0' '0' '0' '0' '1' '0' '1' '1' '0']
    

I want to sum all elements of each row excluding index 0 (the 4 digit
numbers). And then store those sums in a list.

This is what my list of sums should look like:

    
    
    [1, 4, 4, 4, 4, 4, 5, 5, 3,.......,3] (Imagine it was all filled with the right sums)
    

However, this is what my code outputs:

    
    
    number of rows: 16
    number of cols: 15
    num1s before: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
    num1s after : [3, 3, 3, 3, 3, 3, 3, 3, 3, 7, 3, 7, 9, 7]
    

I'm not sure what the error is, but I think it has to do with string/int
conversion. Since my table is in strings, but I convert it to ints for
summing. Debugging it shows the correct results, so I'm not sure where the
error is.

Here is my code:

    
    
    import numpy
    
    print ("Reading..")
    txtfile = open("test1.txt", "r")
    print(txtfile.readline())
    txtfile.close()
    
    r= numpy.genfromtxt('test1.txt',dtype=str,skiprows=1)
    
    for x in range (0,len(r)):
        print(r[x])
    
    allTested = [0] * (len(r[0]) - 1)
    num1s = [0] * (len(r[0]) - 1)
    
    print("number of rows:", len(r))
    print("number of cols:", len(r[0]))
    print("num1s before:",num1s)
    
    for x in range (0,len(r)):
        for y in range(1,len(r[0])):
            num1s[y-1] += int(r[x][y])
    
    
    print("num1s after :",num1s)
    


Answer: Okay. Figured out the answer.

@wajid Farhani was close, but it wasn't working in my case.

His command for np.sum works, but I had to perform some indexing so I can
ignore index 0 of every row. My issue was that I thought indexing 2D array was
done by array[x][y], when it's array[x,y].

Fixed code:

    
    
    import numpy
    
    print ("Reading..")
    txtfile = open("test1.txt", "r")
    print(txtfile.readline())
    txtfile.close()
    
    r= numpy.genfromtxt('test1.txt',dtype=str,skiprows=1)
    
    for x in range (0,len(r)):
        print(r[x])
    
    allTested = [0] * (len(r[0]) - 1)
    num1s = [0] * (len(r))
    
    print("number of rows:", len(r))
    print("number of cols:", len(r[0]))
    print("num1s before:",num1s)
    
    array = numpy.array(r,dtype=int)
    
    s = numpy.sum(array[0:len(array),1:len(array[0])],axis=1).tolist()
    
    print("num1s after :",s)
    

Correct output:

    
    
    num1s before: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
    num1s after : [1, 4, 4, 4, 4, 5, 5, 3, 4, 5, 5, 3, 4, 3, 3, 3]
    

