Python - File manipulation using headings

Question

How would I get python to run through a .txt document, find a specific heading and then put information from each line in to a list for printing? And then once finished, look for another heading and do the same with the information there...

You need to be more specific, show an example file and some code you have so far — jamylak, Apr 21 '13 at 10:50

score 1 · Answer 1 · answered Apr 21 '13 at 11:11

1

If you had a csv file as follows:

h1,h2,h3
a,b,c
d,e,f
g,h,i

Then the following would do as you request (if I understood you correctly)

def getColumn(title,file):
    result = []
    with open(file) as f:
        headers = f.readline().split(',')
        index = headers.index(title)
        for l in f.readlines():
            result.append(l.rstrip().split(',')[index])
    return result

For example:

print(getColumn("h1",'cf.csv') )
>>> ['a', 'd', 'g']

answered Apr 21 '13 at 11:11

HennyH

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Would you like me to explain in detail how it works? Also a simpler and more efficient version could be made by getting substrings based on the comma numbers of the header. – HennyH Apr 21 '13 at 23:34

score 1 · Answer 2 · answered Apr 21 '13 at 11:35

File test.txt

a
b
c
heading1
d
e
f
heading2
g
h
heading3

>>> from itertools import takewhile, imap
>>> with open('test.txt') as f:
        for heading in ('heading1', 'heading2', 'heading3'):
            items = list(takewhile(heading.__ne__, imap(str.rstrip, f)))
            print items


['a', 'b', 'c']
['d', 'e', 'f']
['g', 'h']

Python - File manipulation using headings

2 Answers2