[Tutor] Grep equiv.
Thu, 31 Aug 2000 11:23:10 -0500 (CDT)
Still not able to get exactly what I want. Really a result exactly like
grep does is what I'm looking for. I want to examine a file, line by
line, and return the lines that contain a string that I was searching
for. To do this using string.find, I tried the following. This searches
for the string 'sdb' in a file, and I only want it to kick back the lines
that contain the string.
I think that it's looking at the whole file, if it contains the string, it
spits the whole file back, if it doesn't contain the string, it returns
nothing. How can I break up the piece that I'm feeding the string.find
into lines, so that I can tell it what to do line by line?
I tried to use string.splitfields(line) to break it up, but it used a
whitespace delimeter and divided each line up. If I did this the
string.find choked on the list variable type. Which raises other
questions I have about how I can perform a particular function on all of
the items in a list ( variable, variable, variable, etc.) in one
Further, what would be the preferred way to suck a file in, put each line
in a variable, and each field in each line inside of that? I understand
that I can nest lists, so maybe like file is first line of file and
inside of that there could be several fields? How would I reference them
and how could I get them into a structure like that?
Eventually I want to take say the third field from each line that matches
my "grep-like" function and add them.
filename = sys.argv
file = open(filename)
for line in file.readlines():
result = string.find(line,'sdb')
if result != '-1' :