jo3c wrote:
> i have a 2000 files with header and data
> i need to get the date information from the header
> then insert it into my database
> i am doing it in batch so i use glob.glob('/mydata/*/*/*.txt')
> to get the date on line 4 in the txt file i use
> linecache.getline('/mydata/myfile.txt/, 4)
>
> but if i use
> linecache.getline('glob.glob('/mydata/*/*/*.txt', 4) won't work
glob.glob returns a list of filenames, so you need to call getline once
for each file in the list.
but using linecache is absolutely the wrong tool for this; it's designed
for *repeated* access to arbitrary lines in a file, so it keeps all the
data in memory. that is, all the lines, for all 2000 files.
if the files are small, and you want to keep the code short, it's easier
to just grab the file's content and using indexing on the resulting list:
for filename in glob.glob('/mydata/*/*/*.txt'):
line = list(open(filename))[4-1]
... do something with line ...
(note that line numbers usually start with 1, but Python's list indexing
starts at 0).
if the files might be large, use something like this instead:
for filename in glob.glob('/mydata/*/*/*.txt'):
f = open(filename)
# skip first three lines
f.readline(); f.readline(); f.readline()
# grab the line we want
line = f.readline()
... do something with line ...
</F>
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