Let's say I have this textfile: date.txt. month|day|year
January|20|2014
February|10|
March|5|2013
I want to put 2012 after February|10|. how can i do that?
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2 Answers
You need to read the file into memory, modify the desired line and write back the file.
temp = open('temp', 'wb')
with open('date.txt', 'r') as f:
for line in f:
if line.startswith('February'):
line = line.strip() + '2012\n'
temp.write(line)
temp.close()
shutils.move('temp', 'data.txt')
If you don't want to use a temporary file:
with open('date.txt', 'r+') as f: #r+ does the work of rw
lines = f.readlines()
for i, line in enumerate(lines):
if line.startswith('February'):
lines[i] = lines[i].strip() + '2012\n'
f.seek(0)
for line in lines:
f.write(line)
1 Comment
Aditya Malviya
Doens't work, shutils.move()
You can use the csv module, for example:
import csv
data = [
"January|20|2014",
"February|10|",
"March|5|2013"
]
reader = csv.reader(data, delimiter="|")
for line in reader:
line = [i if i != "" else "2012" for i in line]
print(line)
Please note: csv.reader() take as argument any iterable object. So, you can easily pass it a file object
