StopIteration given by a file iteration that uses nested loops

Question

I'm having some issues with the following block of code. What I'm trying to do is go through a file line by line, and pull out the lines following a line that contains ".W", until it reaches a line that starts with ".I"

with open("cran.all.1400","r") as abstracts:
abstract_list = []
for line in abstracts:
    if (line.startswith(".W")):
        abstract_string = ""
        while not (line.startswith('.I')):
            abstract_string = abstract_string + line
            abstracts.next()
        abstract_list.append(abstract_string)

I've encountered the StopIteration, and some googling has shown me that this occurs when .next() has no value, but I'm not sure how I should be writing this code then.

What I'm unsure of specifically, is how to have the while loop continue going through the lines, and have the for loop pick up where the while loop left off.

score 1 · Accepted Answer · answered Mar 17 '16 at 18:26

1

Use a flag in the for-loop:

with open("cran.all.1400") as abstracts:
    inside = False
    abstract_list = []
    for line in abstracts:
        if line.startswith(".W"):
            inside = True
            abstract_list.append("")
        elif line.startswith(".I"):
            inside = False
        elif inside:
            abstract_list[-1] += line

answered Mar 17 '16 at 18:26

Daniel

42,087
4
55
81

This worked properly, thank you! No lines start with ".W" (only lines following) so this works fine. – wtk219 Mar 17 '16 at 18:50

StopIteration given by a file iteration that uses nested loops

1 Answers1