efficient text file search.

[noro]

Is there a more efficient method to find a string in a text file then:

f=file('somefil e')
for line in f:
if 'string' in line:
print 'FOUND'

?

BTW:
does "for line in f: " read a block of line to te memory or is it
simply calls f.readline() many times?

thanks
amit

[Sion Arrowsmith]

noro <am******@gmail .comwrote:

>OK, am not sure why, but

fList=file('so mefile').read()
if fList.find('str ing') != -1:
print 'FOUND'

works much much faster.

it is strange since i thought 'for line in file('somefile' )' is
optemized and read pages to the memory,

Step back and think about what each is doing at a high level of
description: file.read reads the contents of the file into memory
in one go, end of story. file.[x]readlines reads (some or all of)
the contents of the file into memeory, does a linear searches on it
for end of line characters, and copies out the line(s) into some
new bits of memory. Line-by-line processing has a *lot* more work
to do (unless you're read()ing a really big file which is going to
make heavy demands on memory allocation) and it should be no
surprise that it's slower.

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