On Aug 13, 11:41 pm, naaman <arphak...@gmail.com> wrote: > On Aug 13, 7:50 am, Dave Angel <da...@ieee.org> wrote: > > > > > naaman wrote: > > > On Aug 12, 1:35 pm, Dave Angel <da...@ieee.org> wrote: > > > >> naaman wrote: > > > >>> I'm writing my first Python script and > > >>> I want to use fileinput to open a file in r+ mode. > > >>> Tried fileinput.input(sys.argv[1:],"r+") but that didn't work. > > >>> ANy ideas? > > > >>> Need to find and overwrite a line in a file several times. > > >>> I can do it using open and seek() etc. but was wondering if I can use > > >>> fileinput. > > > >>> thanks; > > > >> I haven't used it, but check out the 'inplace' keyword parameter. > > > >> DaveA > > > > I've only Python for a week so I'm not sure what inplace does > > > You should read the docs for it > > (http://www.python.org/doc/2.6.2/library/fileinput.html ), > > but it's not very clear to me either So I dug up an example on the web: > > (ref: http://effbot.org/librarybook/fileinput.htm) > > > import fileinput, sys > > > for line in fileinput.input(inplace=1): > > # /convert Windows/DOS text files to Unix files/ > > if line[-2:] == "\r\n": > > line = line[:-2] + "\n" > > sys.stdout.write(line) > > > The inplace argument tells it to create a new file with the same name as > > the original (doing all the necessary nonsense with using a scratch > > file, and renaming/deleting) for each file processed. Stdout is pointed > > to that new version of the file. Notice that you have to explicitly > > write everything you want to wind up in the file -- if a given line is > > to remain unchanged, you just write "line" directly. > > > If you're new to Python, I do not recommend trying to do open/seek to > > update a text file in place, especially if you're in DOS. There are > > lots of traps. the inplace method of fileinput avoids these by > > implicitly creating temp files and handling the details for you, which > > probably works great if you're dealing with text, in order. > > > DaveA > > here's the solution > > import fileinput, sys > > for line in fileinput.input(sys.argv[1],inplace=1): > if (line[:-1]==r'drew'): > line=line.replace(line,"fancy dog") > sys.stdout.write(line) > > I want to replace drew in my input file with fancy dog. > Tested with this input file > angel > heaven > flying monkees > lazy dogs > drew > blue sky > veritas > > and got this > angel > heaven > flying monkees > lazy dogs > fancy dog > blue sky > veritas > > So drew was replaced with fancy dog. > Thanks to your inputs I got this solved. :-))
oops there should be a +"\n" after "fancy dog" line=line.replace(line,"fancy dog"+"\n") -- http://mail.python.org/mailman/listinfo/python-list
