Create Text files from a loop with Python? [closed]

Question

I need to create some files to hyperlink to from Arcmap. I have a folder of jpeg files (100.jpg, 101.jpg etc...). I need to loop through them and create a text file of the same name except replace the *.txt at the end with *.fsv (100.fsv, 101.fsv etc...). This text file of the same name (with the txt replaced with fsv) is a set of instructions on how to open that jpeg in a piece of software so I need to write some instruction in it for example 100.fsv would contain:

open=100.jpg set to 100

everything in the txt file is static except for the name of the jpg it opens. Thanks for any help.

Answer 1

This is one way to go about it:

This python snippet will loop over a directory, get all of the filenames that end with a .jpg extension and the create a new text file with the new .fsv extension - this file will contain whatever text you choose to write to it.

import glob
import os
os.chdir("\dir") #the directory containing your .jpegs
    for file in glob.glob("*.jpg"): #iterates over all files in the directory ending in .jpg        
        f = open(( file.rsplit( ".", 1 )[ 0 ] ) + ".fsv", "w") #creates a new file using the .jpg filename, but with the .fsv extension
        f.write('whatever you want in the text file') #write to the text file
        f.close()

You will end up with a new .fsv file for every .jpg in the original folder. The above code will just write all of the new files to the same folder that the .jpgs are stored in. This is by no means beautiful code (no error checking), but it's simple and it works.

Answer 2

Just to add on to the other answers, you can avoid having to explicitly call the file object's close() method if you use a with statement (which automatically calls close() even if an exception is raised):

with open(filename, 'w') as f:
    f.write("open=" + jpg + " set to 100")

Also don't forget to write a line-ending if that is the intention...

Answer 3

Because you're asking in GIS, I'm including arcpy in my answer. ;)

import arcpy
from arcpy import env

env.workspace = r'C:\your\path\here'

jpgList = arcpy.ListFiles("*.jpg")
for jpg in jpgList:
    jpgnum = jpg[:-4]
    filename = jpgnum + '.fsv'
    f = open(filename, 'w')     
    f.write("open=" + jpg + " set to 100")     
    f.close()

And that's it!