summing up values of columns from multiple files

Question

I have a small problem here, I\'m trying to sum up entries from multiple files (50), and each of them contain 3 columns. for example, using the first 3 files: file1.txt, fi

Answer 1

http://docs.scipy.org/doc/numpy/reference/generated/numpy.loadtxt.html load into numpy array and then sum arrays.

Answer 2

#!/usr/bin/python
b_list = []
for l in range(1,4):
    file=open('/Users/sgeorge/file%i.txt' % l, 'r')
    m1=[(i.strip()) for i in file]
    for j in m1:
        b_list.append(filter(None,[(k.strip()) for k in j]))
#print b_list
a = [[0,0,0],[0,0,0],[0,0,0]]
for i in range(0,9,3):
    a[0][0] += int(b_list[i][0])
    a[0][1] += int(b_list[i][1])
    a[0][2] += int(b_list[i][2])
for i in range(1,9,3):
    a[1][0] += int(b_list[i][0])
    a[1][1] += int(b_list[i][1])
    a[1][2] += int(b_list[i][2])

for i in range(2,9,3):
    a[2][0] += int(b_list[i][0])
    a[2][1] += int(b_list[i][1])
    a[2][2] += int(b_list[i][2])

for j in a:
    print j[0],j[1],j[2]

Output:

$ python stack.py 
9 6 6
4 11 8
12 11 13

The above script is meant to handle only three files (file1.txt,file2.txt and file3.txt)

If you want to handle 50 such files, use following:

#!/usr/bin/python
b_list = []
for l in range(1,51):
    file=open('/Users/sgeorge/file%i.txt' % l, 'r')
    m1=[(i.strip()) for i in file]
    for j in m1:
        b_list.append(filter(None,[(k.strip()) for k in j]))
#print b_list
a = [[0,0,0],[0,0,0],[0,0,0]]
for i in range(0,150,3):
    a[0][0] += int(b_list[i][0])
    a[0][1] += int(b_list[i][1])
    a[0][2] += int(b_list[i][2])
for i in range(1,150,3):
    a[1][0] += int(b_list[i][0])
    a[1][1] += int(b_list[i][1])
    a[1][2] += int(b_list[i][2])

for i in range(2,150,3):
    a[2][0] += int(b_list[i][0])
    a[2][1] += int(b_list[i][1])
    a[2][2] += int(b_list[i][2])

for j in a:
    print j[0],j[1],j[2]

Update:

>>> a=1
>>> b=1.1
>>> type(a)
<type 'int'>
>>> type(b)
<type 'float'>
>>> float(a)+float(b)
2.1
>>> 

My above script will not handle floating numbers. For handling the same, use the following:

#!/usr/bin/python
b_list = []
for l in range(1,4):
    file=open('/Users/sgeorge/file%i.txt' % l, 'r')
    m1=[(i.strip()) for i in file]
    for j in m1:
        b_list.append(j.replace('\n','').split(' '))
#print b_list
a = [[0,0,0],[0,0,0],[0,0,0]]
for i in range(0,9,3):
    a[0][0] += float(b_list[i][0])
    a[0][1] += float(b_list[i][1])
    a[0][2] += float(b_list[i][2])
for i in range(1,9,3):
    a[1][0] += float(b_list[i][0])
    a[1][1] += float(b_list[i][1])
    a[1][2] += float(b_list[i][2])
for i in range(2,9,3):
    a[2][0] += float(b_list[i][0])
    a[2][1] += float(b_list[i][1])
    a[2][2] += float(b_list[i][2])
for j in a:
    print j[0],j[1],j[2]

Output:

$ python stack.py 
9.0 6.0 6.0
4.0 11.0 8.0
12.0 11.0 13.0

Answer 3

In [1]: import numpy as np

In [2]: from StringIO import StringIO

In [3]: txt ="""2 3 4
   ...: 1 5 6
   ...: 5 4 7"""

In [4]: f = StringIO(txt)

In [5]: arr = np.loadtxt(f,dtype = int)

In [6]: np.sum(arr,axis = 0)
Out[6]: array([ 8, 12, 17])