Help with some python 2.0 code

[ironmonkey69]

I need help to get this script to accept more than one number in the 'elem = ' line so that I will be able to zero more than one line at a time. Right now I am able to get it to do one line at a time. This script is written using python 2.0.

Here is what the text file looks like:

#Number of Bits
12
#Data
0 0 0 0 0 0 0 0 0 0 0 0
12 5 3 4 6 4 5 4 7 5 5 10
24 9 7 7 13 7 9 9 14 10 10 20

and this is what it does:

#Number of Bits
12
#Data
0 0 0 0 0 0 0 0 0 0 0 0
12 0 3 4 6 4 5 4 7 5 5 10
24 0 7 7 13 7 9 9 14 10 10 20

Here is what the Python 2.0 code looks like:

def nthzero(dataList, nth, n): 
''' 
Replace the nth element of each list in the data list with 'n' 
''' 
for item in dataList: 
item[nth] = n 
return dataList 
 
 
fn = 'outfile.txt' 
f = open(fn) 
 
s = f.next() 
prefix = s 
while s.strip() != '#Data': 
s = f.next() 
prefix += s 
 
lineList = [line.strip().split() for line in f] 
 
f.close() 
elem = 0 
repl = '0' 
lineList = nthzero(lineList, elem, repl) 
 
fn1 = 'outfile.txt' 
f = open(fn1, 'w') 
outList = [] 
for line in lineList: 
outList.append(' '.join(line)) 
 
f.write('%s%s' % (prefix, '\n'.join(outList))) 
f.close()
 

[bvdet]

I need help to get this script to accept more than one number in the 'elem = ' line so that I will be able to zero more than one line at a time. Right now I am able to get it to do one line at a time. This script is written using python 2.0.

Here is what the text file looks like:

#Number of Bits
12
#Data
0 0 0 0 0 0 0 0 0 0 0 0
12 5 3 4 6 4 5 4 7 5 5 10
24 9 7 7 13 7 9 9 14 10 10 20

and this is what it does:

#Number of Bits
12
#Data
0 0 0 0 0 0 0 0 0 0 0 0
12 0 3 4 6 4 5 4 7 5 5 10
24 0 7 7 13 7 9 9 14 10 10 20

Here is what the Python 2.0 code looks like:

def nthzero(dataList, nth, n): 
''' 
Replace the nth element of each list in the data list with 'n' 
''' 
for item in dataList: 
item[nth] = n 
return dataList 
 
 
fn = 'outfile.txt' 
f = open(fn) 
 
s = f.next() 
prefix = s 
while s.strip() != '#Data': 
s = f.next() 
prefix += s 
 
lineList = [line.strip().split() for line in f] 
 
f.close() 
elem = 0 
repl = '0' 
lineList = nthzero(lineList, elem, repl) 
 
fn1 = 'outfile.txt' 
f = open(fn1, 'w') 
outList = [] 
for line in lineList: 
outList.append(' '.join(line)) 
 
f.write('%s%s' % (prefix, '\n'.join(outList))) 
f.close()
 

This is untested. Pass a list of indices to the function nthzero(). The function has an additional loop. Watch out for indentation. The code you posted had none, so it would not work.

def nthzero(dataList, nthList, n):
    '''
    Replace the nth element of each list in dataList with 'n'
    '''
    for nth in nthList:
        for item in dataList:
            try:
                item[nth] = n
                print dataList
            except IndexError, n:
                print n
    return dataList
 
fn = 'outfile.txt' 
f = open(fn) 
 
s = f.readline()
prefix = s
while s.strip() != '#Data':
    s = f.readline()
    prefix += s
 
lineList = [line.strip().split() for line in f.readlines()] 
 
f.close() 
elem = [1,3,5,8,12]
repl = '0' 
lineList = nthzero(lineList, elem, repl) 
 
fn1 = 'outfile.txt' 
f = open(fn1, 'w')
 
outList = []
 
for line in lineList:
    outList.append(' '.join(line))
 
f.write('%s%s' % (prefix, '\n'.join(outList)))
f.close()

I threw in an index of 12 to test the try-except statement.

[ironmonkey69]

Can you add some comments to the code to help me get a better a better understanding of which sections do what?