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  1. PO
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    <p>You are really confused on how to use a file.</p> <p>First of all, why are you doing <code>int(open(filename, "w"))</code>? To open a file for writing just use:</p> <pre><code>outfile = open(filename, "w") </code></pre> <p>Then files does not support item assignment, so doing <code>fileobject[key]</code> does not make sense. Also note that opening a file with <code>"w"</code> <em>deletes</em> the previous contents! So if you want to modify the contents of a file you should use <code>"r+"</code> instead of <code>"w"</code>. You then have to read the file and parse its contents. In your case is probably better to first read the contents and then create a new file to write the new contents.</p> <p>To write a list of numbers to a file do:</p> <pre><code>outfile.write(','.join(str(number) for number in list2)) </code></pre> <p><code>str(number)</code> "converts" an integer into its string representation. <code>','.join(iterable)</code> joins the elements in <em>iterable</em> using a comma as separator and <code>outfile.write(string)</code> writes <em>string</em> to the file.</p> <p>Also, put the import outside the function(at the beginning of the file possibly) and you do not need to repeat it everytime you use the module.</p> <p>A complete code could be:</p> <pre><code>import tkinter.filedialog def replace(): drawfilename = tkinter.filedialog.askopenfilename() # read the contents of the file with open(drawfilename, "r") as infile: numbers = [int(number) for number in infile.read().split(',')] del numbers[-3:] # with automatically closes the file after del numbers[-3:] input_list = input("Enter three numbers separated by commas: ") # you do not have to strip the spaces. int already ignores them new_numbers = [int(num) for num in input_list.split(',')] numbers = new_numbers + numbers #drawfilename = tkinter.filedialog.askopenfilename() if you want to reask the path # delete the old file and write the new content with open(drawfilename, "w") as outfile: outfile.write(','.join(str(number) for number in numbers)) </code></pre> <p>Update: If you want to deal with more than one sequence you can do this:</p> <pre><code>import tkinter.filedialog def replace(): drawfilename = tkinter.filedialog.askopenfilename() with open(drawfilename, "r") as infile: sequences = infile.read().split(None, 2)[:-1] # split(None, 2) splits on any whitespace and splits at most 2 times # which means that it returns a list of 3 elements: # the two sequences and the remaining line not splitted. # sequences = infile.read().split() if you want to "parse" all the line input_sequences = [] for sequence in sequences: numbers = [int(number) for number in sequence.split(',')] del numbers[-3:] input_list = input("Enter three numbers separated by commas: ") input_sequences.append([int(num) for num in input_list.split(',')]) #drawfilename = tkinter.filedialog.askopenfilename() if you want to reask the path with open(drawfilename, "w") as outfile: out_sequences = [] for sequence, in_sequence in zip(sequences, input_sequences): out_sequences.append(','.join(str(num) for num in (in_sequence + sequence))) outfile.write(' '.join(out_sequences)) </code></pre> <p>This should work with any number of sequences. Note that if you have an extra space somewhere you'll get wrong results. If possible I'd put these sequences on different lines.</p>
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    1. COYou are write. I am completely new to this and am totally confused. THank you for your help. Much appreciated
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    2. COMAy I add a question to the original one. How would the script look if the txt file contained two lists separated by spaces and one wanted to write to both lists eg 1,2,3,4,5 8,9,10,11? Ask for two sets of numbers to be entered. THe soltion above works perfectly, thank you very much
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    3. CO@user1478335 You mean you have a file with a single line of the form `1,2,3,...,11 SPACE 3,4,5,6,..,12` and you want to ask the user two sequences and update the file? Should the input from the user be treated as before, deleting the last three items in the sequence and adding the numbers the user provides at the beginning?
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