[Tutor] summer_v04.py

[Kent Johnson]

Christopher Spears wrote:
> I've been working on a version of a script I found in
> "Programming Python".  The helpful users of this forum
> gave me some advice to make the code less wordy.  Here
> is the code:
> 
> #!/usr/bin/python
> import string
> 
> def find_longest_line(fileName):
> 	line_list = [line.split() for line in open(fileName,
> 'r').readlines()]
> 	numCols = max(len(cols) for cols in line_list)
> 	#print numCols
> 	return numCols
> 
> def summer(fileName):
> 	length_longest_col = find_longest_line(fileName)
> 	sums = [0] * length_longest_col
> 	for line in line_list:
> 		cols = string.split(line)
> 		for i in range(len(cols)):
> 			sums[i] = sums[i] + float(cols[i])
> 	return sums
> 			
> if __name__ == '__main__':
> 	import sys
> 	print summer(sys.argv[1])
> 	#print find_longest_line(sys.argv[1])
> 	
> The code opens a file called table.txt:
> 1       5       10      2       1.0
> 2       10      20      4       2.0     3
> 3       15      30      8       3       2       1
> 4       20      40      16      4.0
> 
> Then the script adds the columns in the file together.
> 
> However, when I run the script, I get a syntax error:

When you fix the syntax error, which others have shown how to do, you 
will get a NameError in summer() because the name line_list is private 
to find_longest_line(). The simplest way to fix this would be to combine 
find_longest_line() and summer() or to read the file lines in summer() 
and pass line_list, instead of the file name, to find_longest_line().

Kent