CODEWITHSUNDEEP
python
chickflick91
chickflick91

Reputation: 63

how to randomly select a file in a directory open it and write into it?

I am trying to randomly select a file in folder open it and write into it. I have:

import os, random
x = random.choice(os.listdir("F:\\1\\"))
y =open(x, 'w')
y.write('Hello World')

but nothing gets written. any ideas how to fix it?

Upvotes: 1

Views: 227

Answers (3)

Joe Iddon
Joe Iddon

Reputation: 20414

This is very dangerous, as you opening a file for writing blanks it of all its content, so you are effectively randomly destroying one file.

Anyway, if that is what you want, use a with statement and remember that os.listdir returns the file names in a directory, not paths, so you need to use os.path.join to join the 2 parts together:

import os, random
path = r"F:\1"
x = random.choice(os.listdir(path))
with open(os.path.join(path, x), 'w') as y:
   y.write('Hello World')

Upvotes: 1

jmd_dk
jmd_dk

Reputation: 13090

The os.listdir command lists all files in the given directory. It does not prepend the path (the directory name). You therefore have to do

import os, random
dirname = "F:\\1\\"
x = dirname + random.choice(os.listdir(dirname))
y = open(x, 'w')
y.write('Hello World')

Also, it is good practice to close a file once you are done writing to it. You can do this by y.close(). This is done for you automatically if you use a with statement like so:

import os, random
dirname = "F:\\1\\"
x = dirname + random.choice(os.listdir(dirname))
with open(x, 'w') as y:
    y.write('Hello World')

Upvotes: 0

Ajax1234
Ajax1234

Reputation: 71451

The issue is that you are not closing the file:

import os, random
x = random.choice(os.listdir("F:\\1\\"))
y =open(x, 'w')
y.write('Hello World\n') 
y.close()

Upvotes: 0

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