Question

I have a v. large text document (no file extension) that has information about a different file on every line in the following format:

VariableOne|VariableTwo|VaraibleThree

The pipe separates the different variables.
However, within some ‘VaraibleTwo’s there may also be pipes.

I need to extract that information from the text document so that I can manipulate the information. For example:

Name = VariableOne From The Text Document
Middle Name(s) = VariableTwo From The Text Document
Last Name = VariableThree From The Text Document

This needs to be done in Python 3 with six variables all together and only the second variable containing pipes.

Thanks for any help you can give!

Answer 1

How about:

>>> s = 'a|b|more b|yet more b|c|d|e|f'
>>> a, *b, c, d, e, f = s.split('|')
>>> b = '|'.join(b)
>>> 
>>> a,b,c,d,e,f
('a', 'b|more b|yet more b', 'c', 'd', 'e', 'f')

where you could replace the explicit naming by slicing the split result, which might be a little more general. As for reading the file, the usual pattern is

with open('somefile') as fp:
    for line in fp:
        a, *b, c, d, e, f = line.strip().split('|')
        b = '|'.join(b)
        # do something

which doesn’t read the entire file into memory at once, which is handy for large files.

UPDATE: if you have to loop over all the lines, but only process one, then you could use

with open('somefile') as fp:
    for i, line in enumerate(fp):
        if i == some_number:
            a, *b, c, d, e, f = line.strip().split('|')
            b = '|'.join(b)

On the other hand, if there’s only one line you need to extract and process, you can use the linecache module:

def proc(filename, lineno):
    line = linecache.getline(filename, lineno)
    a, *b, c, d, e, f = line.strip().split('|')
    b = '|'.join(b)
    # do something

Although to be honest, I think I prefer Karl Knechtel’s two-argument split approach because it’s more general.