Automate string replacing in python

Question

I have a python file named file_1.py

It has some code in which I just have to change a word: "file_1" to: "file_2" and save it as file_2.py, then again replace 'file_1' with 'file_3' and save it as file_3.py

I have to do this for say 100 times, creating 100 python files: file_1.py,file_2.py......file_100.py

I wrote a code which can replace a string, but I am stuck to write a loop which automates it. Any leads?

with open("path/to/file_1.py") as f:
content = f.read()

new_content = content.replace("file_1","file_2")

with open("path/to/file_2.py", "w") as f:
    f.write(new_content)

willeM_ Van Onsem · Accepted Answer · 2017-04-11 10:37:56Z

5

You can simply use a for loop around the replacing and writing:

with open("path/to/file_1.py") as f:
    content = f.read()

for i in range(2,101):
    new_content = content.replace("file_1","file_%s"%i)

    with open("path/to/file_%s.py"%i, "w") as f:
        f.write(new_content)

So here you repeat the process with i ranging from 2 (inclusive) to 101 (exclusive). And for each such i you .replace(..) the content such that "file1" is replaced by "file_%s"%i (the modulo % on a string here means that the %s will be replaced by the representation of i).

Then you open a file "path/to/file_%s.py"%i (again with %s being replaced by the representation of i) and you write the content to that file.

You can of course read the content of file_1 in every iteration, but I assume the content is fixed, so reading it once at the beginning of the program will be more efficient.

answered Apr 11, 2017 at 10:37

willeM_ Van Onsem

482k33 gold badges483 silver badges624 bronze badges

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

2 Comments

Rico Over a year ago

what if file 1 updates quickly and before finishing writing 100 files it has already, better would be to discard writing if change detected before loop finishes

willeM_ Van Onsem Over a year ago

@Rico: well given the file changes a nonosecond after the program stops, that's the same problem, and then the program is not alive anymore to fix it. In my opinion it is better to make it the responsibility of the caller to ensure that contracts are valid: a bash script that would call this Python script could for instance lock the file, etc.

Collectives™ on Stack Overflow

Automate string replacing in python

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related