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.[code=Python]def nthzero(dataLis t, 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().sp lit() for line in f.readlines()]

f.close()
elem = [1,3,5,8,12]
repl = '0'
lineList = nthzero(lineLis t, 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(outLi st)))
f.close()[/code]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?