Value error when matching tables

Question

When I run the program, I get ValueError. I don't know why that is. The program is:

    def get_coordinates(infile, delimiter):
        new_list = []
        with open(infile, 'r') as f:
            for line in f:
                x, y = [float(i) for i in line.strip().split('delimiter')]


        new_list.append('%0.4f,%0.4f' % (x, y))

return new_list


LIST1 = get_coordinates('table1.txt', ',')
LIST2 = get_coordinates('table2.txt', ',')

NEW_LIST = list(set(LIST1) & set(LIST2))


with open('outfile.txt', 'w') as outfile:
    for xy in NEW_LIST:

        outfile.write('%s\n' % xy)

I get the following:

ValueError 

    202             else:
    203                 filename = fname
--> 204             __builtin__.execfile(filename, *where)


---> 18 LIST1 = get_coordinates('table1.txt', ',')
     19 LIST2 = get_coordinates('table2.txt', ',')
     20 


      7     with open(infile, 'r') as f:
      8         for line in f:
----> 9             x, y = [float(i) for i in line.strip().split('delimiter')]

222.27515,  8.0208306eral for float(): 222.30777,  8.9363889

Answer 1

You are seeing this because there is an error in your logic and/or code for pulling the floats out of the lines from your file. This is resulting in a call to float() that looks something like this:

>>> float('222.30777,  8.9363889')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: invalid literal for float(): 222.30777,  8.9363889

Currently you are trying to split each line on the string 'delimiter', so for example 'FOOdelimiterBAR'.split('delimiter') would result in ['FOO', 'BAR'].

From looking at the error message it looks like the floats are separated by a comma, so if you have a variable named delimiter then you should use line.strip().split(delimiter), or just use line.strip().split(',') if you know you want to be splitting on comma.

Answer 2

Try without the quotes around delimiter

x, y = [float(i) for i in line.strip().split(delimiter)]

You are trying to use the string 'delimiter' as the splitting char, not what the variable delimiter contains.