How to create a string with loop in python and save it in file

Question

I would like to create a string:

"FILE1 blabla2\nFILE2 blabla4 ..."

and save it in a file. Please note that, in each line of the file the second integer is the double of the first. At the end it should look like:

FILE1 blabla2
FILE2 blabla4
...

but because I have a big amount of lines of this pattern, it is inefficient to do it manually. I would like to use python for this purpose. I can imagine it could be probably done somehow with:

join()

but I don't know exactly how. Any help is appreciated.

Sukrit Kalra · Accepted Answer · 2014-04-02 13:29:52Z

3

Assuming you have an upper limit for the numbers, you can do something like.

>>> "\n".join(["FILE{} blabla{}".format(x, x*2) for x in xrange(1, 10)])
'FILE1 blabla2\nFILE2 blabla4\nFILE3 blabla6\nFILE4 blabla8\nFILE5 blabla10\nFILE6 blabla12\nFILE7 blabla14\nFILE8 blabla16\nFILE9 blabla18'

and then just write these to a file using.

with open('random.txt', 'a') as f:
    f.write("\n".join(["FILE{} blabla{}".format(x, x*2) for x in xrange(10)]))

answered Apr 2, 2014 at 13:29

Sukrit Kalra

34.7k7 gold badges73 silver badges71 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Amaury Medeiros · Accepted Answer · 2014-04-02 13:38:03Z

1

n_lines = 2 # Actual number of lines you want

output = "\n".join(["FILE{} blabla{}".format(x, x*2) for x in xrange(1, n_lines+1)])

file = open("your_output_file", "w")

for line in output.split("\n"):
    file.write("{}\n".format(line))
file.close()

answered Apr 2, 2014 at 13:38

Amaury Medeiros

2,2974 gold badges28 silver badges43 bronze badges

Comments

El Bert · Accepted Answer · 2014-04-02 13:44:06Z

1

You can either do that in (almost) one statement:

with open("blabla.txt", "w") as bla:
    bla.write("\n".join("FILE%d blabla%d" % (i, i*2) for i in range(1, 5)))

or you can prepare your list of blabla if you need to reuse it later on:

blabla = ["FILE%d blabla%d" % (i, i*2) for i in range(1, 5)] 
with open("blabla.txt", "w") as bla:
    for item in blabla:
        print >> bla, item # Note that this syntax add the new line without using "\n".join

answered Apr 2, 2014 at 13:44

El Bert

3,0421 gold badge31 silver badges38 bronze badges

Comments

x3al · Accepted Answer · 2014-04-02 15:05:48Z

1

list_of_strings = [] 
for i in range(3):
    list_of_strings.append("FILE{0} blabla{1}".format(i, i*2))  # or whatever you need

'\n'.join(list_of_strings)

edited Apr 2, 2014 at 15:05

answered Apr 2, 2014 at 13:30

x3al

5861 gold badge8 silver badges26 bronze badges

Comments

Ska · Accepted Answer · 2014-04-02 13:32:19Z

0

I'll give you hints from which you can figure out very easily:

https://wiki.python.org/moin/ForLoop

https://docs.python.org/2/tutorial/inputoutput.html#reading-and-writing-files

answered Apr 2, 2014 at 13:32

Ska

6,95815 gold badges55 silver badges75 bronze badges

Collectives™ on Stack Overflow

How to create a string with loop in python and save it in file

5 Answers 5

Comments

Comments

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

Comments

Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related