Eliminate part of a file in python

Question

Hi all. In the below file I have 3 occurrences of '.1'. I want to eliminate the last one and write the rest of file to a new file. Kindly suggest some way to do it in PYTHON and thank you all.

d1dlwa_ a.1.1.1 (A:) Protozoan/bacterial hemoglobin {Ciliate (Paramecium caudatum) [TaxId: 5885]} slfeqlggqaavqavtaqfyaniqadatvatffngidmpnqtnktaaflcaalggpnawt

Answer 1

If the file's not too horrendously huge, by far the simplest approach is:

f = open('oldfile', 'r')
data = f.read()
f.close()

data = data.replace('.1.1.1', '.1.1')

f = open('newfile', 'w')
f.write(data)
f.close()

If the file IS horrendously huge, you'll need to read it and write it by pieces. For example, if each line ISN'T too horrendously huge:

inf = open('oldfile', 'r')
ouf = open('newfile', 'w')
for line in inf:
    line = line.replace('.1.1.1', '.1.1')
    ouf.write(line)
ouf.close()
inf.close()

Answer 2

You can have something like this :

line = line.split(" ")
line[0] = line[0][0:line[0].rindex(".")]
print " ".join(line)

Not the prettiest code, but from my console tests, it works.

Answer 3

Works with any size file:

open('newfile', 'w').writelines(line.replace('.1.1.1', '.1.1') 
                                for line in open('oldfile'))