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POPython trying to write string to file then read string and eval, but something went wrong
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copied!<p>I am trying to write a very simple script that would simulate a pocket secretary for my homework, but I have a small issue. I want all my data to be saved in a file (abstract form) each time I exit the program and then when i boot it up I want to read that file, eval(stack) (basically load the data into memory) then verify if it's valid ... anything that isn't is deleted. This is what I've done:</p> <pre><code> def loadToString (stack): f = open ("data.txt", "w") load_stack = str(stack) #convert to string f.write (load_stack) #write in file f.close() def loadFromString (): f = open ("data.txt", "r") load_stack = f.readline() #read string if (load_stack == "" or load_stack == " " or load_stack == None): stack = [] return stack else: stack = eval(load_stack) #trying to convert from string to list f.close () </code></pre> <p>My problem is when I look into the file ... it's not really a string because it lacks the apostrophes <"> thus when I try to "eval (stack)" something goes wrong and my "memory" ends up being empty (when I try to print the stack it's empty -None-)</p> <p>I cannot for the life of me understand why this is happening. Also I'm ok with a quick fix (artificially adding apostrophes in the .txt file)</p> <p>I have no idea how to check if a file is empty or if I read an empty line so I'd also appreciate if you could help me with the "if" statement in "loadFromString". About eval () ... like I said this is just homework so I'm not afraid about any malicious intents.</p>

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