Vfrdtyky

I have a folder with csv formated documents with a .arw extension. Files are named as 1.arw, 2.arw, 3.arw ... etc.

I would like to write a code that reads all the files, checks and replaces the forwardslash / with a dash -. And finally creates new files with the replaced character.

The code I wrote as follows:

for i in range(1,6):

    my_file=open("/path/"+str(i)+".arw", "r+")

    str=my_file.read()



    if "/" not in str:

        print("There is no forwardslash")

    else:

        str_new = str.replace("/","-")

        print(str_new)



        f = open("/path/new"+str(i)+".arw", "w")

        f.write(str_new)

        my_file.close()

But I get an error saying:

'str' object is not callable.

How can I make it work for all the files in a folder? Apparently my for loop does not work.

The actual error is that you are replacing the built-in str with your own variable with the same name, then try to use the built-in str() after that.

Simply renaming the variable fixes the immediate problem, but you really want to refactor the code to avoid reading the entire file into memory.

import logging

import os



for i in range(1,6):

    seen_slash = False

    input_filename = "/path/"+str(i)+".arw"

    output_filename = "/path/new"+str(i)+".arw"

    with open(input_filename, "r+") as input, open(output_filename, "w") as output:

        for line in input:    

           if not seen_slash and "/" in line:

               seen_slash = True

            line_new = line.replace("/","-")

            print(line_new.rstrip('n')) # don't duplicate newline

            output.write(line_new)

    if not seen_slash:

        logging.warn("{0}: No slash found".format(input_filename))

        os.unlink(output_filename)

Using logging instead of print for error messages helps because you keep standard output (the print output) separate from the diagnostics (the logging output). Notice also how the diagnostic message includes the name of the file we found the problem in.

Going back and deleting the output filename when you have examined the entire input file and not found any slashes is a mild wart, but should typically be more efficient.

This is how I would do it:

for i in range(1,6):

    with open((str(i)+'.arw'), 'r') as f:

        data = f.readlines()



        for element in data:

            element.replace('/', '-')

        f.close()

    with open((str(i)+'.arw'), 'w') as f:

        for element in data:

            f.write(element)

        f.close()

this is assuming from your post that you know that you have 6 files

if you don't know how many files you have you can use the OS module to find the files in the directory.