Can I know what this error means and how to resolve this?-CodePudding

So uh I'm a new python learner trynna make an ASCII image converter.. So I wrote a code that I got off from youtube and it's giving me errors.. I reviewed the video and everything's fine

Heres the code

        #note: READ THIS OR WONT WORK
    #bassically to make this work you need to place this piece o code inside the same folder as your image thats being converted
    #then run the code and write the file name and extension name (.jpg, .png, etc.)
    #should run..
    
    
    #the ascii import
    import PIL.Image
    
    #things to build the output image
    #can be changed but this variety is decent
    ASCII_CHARS = ["@", "#", "S", "%", "?", "*", " ", ";", ":", ",", "."]
    
    #resizing image
    #pretty confusing but just keep this piece
    def resize_image(image, new_width=100):
        width, height = image.size
        ratio = height / width
        new_height = int(new_width * ratio)
        resized_image = image.resize((new_width, new_height))
        return(resized_image)
    
    #making stuff grayscale
    #this is done cus ASCII dont got any integerated colour thing
    #defining the graying variable and then applying it to the image
    def grayify(image):
        grayscale_image = image.convert("L")
        return(grayscale_image)
    
    #make the pixels the ASCII combination mentioned above (mixture of #'s and $'s and whatever)
    def pixels_to_ascii(image):
        pixels = image.getdara()
        characters = "".join([ASCII_CHARS[pixel//25] for pixel in pixels])
        return(characters)
    
    def main(new_width=100):
        #opening source image
        path = input ("Enter pathname for image:\n")
        try:
            image = PIL.Image.open(path)
        #if no pathname found
        except:
            print(path, "isnt a valid pathname, try another one bro")
    
        #define the image to make it gray then resize the gray output
        new_image_data = pixels_to_ascii(grayify(resize_image(image)))
    
        #formattin'
        pixel_count = len(new_image_data)
        #'ascii_image' is the head of everything where all grayscales and widths and ratios and whatnot is connected
        ascii_image = "\n".join(new_image_data[i:(i new_width)] for i in range(0, pixel_count, new_width))
    
        #printing!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
        print(ascii_image)
    
        #save result
        with open("ascii_image.txt", "w") as f:
            f.write(ascii_image)
    main()

And here's the errors

    Traceback (most recent call last):
      File "C:\Users\user\PycharmProjects\pythonProject\random\ASCII.py", line 59, in <module>
        main()
      File "C:\Users\user\PycharmProjects\pythonProject\random\ASCII.py", line 46, in main
        new_image_data = pixels_to_ascii(grayify(resize_image(image)))
    UnboundLocalError: local variable 'image' referenced before assignment

Process finished with exit code 1

So i wanna know whats wrong and what these errors means

CodePudding user response：

If image = PIL.Image.open(path) generates an exception, then the variable image is never assigned a value. Then, you get the error when you try to reference it here: new_image_data = pixels_to_ascii(grayify(resize_image(image))).

You need to update your except clause to either exit the program or assign another value to image.

CodePudding user response：

Which means python looking for variable called image & It's not found...You alredy decleraed image var in try block...But, Some how code not enetering into Try block...Try moving code below except and move code to try block

#note: READ THIS OR WONT WORK
#bassically to make this work you need to place this piece o code inside the same folder as your image thats being converted
#then run the code and write the file name and extension name (.jpg, .png, etc.)
#should run..


#the ascii import
import PIL.Image

#things to build the output image
#can be changed but this variety is decent
ASCII_CHARS = ["@", "#", "S", "%", "?", "*", " ", ";", ":", ",", "."]

#resizing image
#pretty confusing but just keep this piece
def resize_image(image, new_width=100):
    width, height = image.size
    ratio = height / width
    new_height = int(new_width * ratio)
    resized_image = image.resize((new_width, new_height))
    return(resized_image)

#making stuff grayscale
#this is done cus ASCII dont got any integerated colour thing
#defining the graying variable and then applying it to the image
def grayify(image):
    grayscale_image = image.convert("L")
    return(grayscale_image)

#make the pixels the ASCII combination mentioned above (mixture of #'s and $'s and whatever)
def pixels_to_ascii(image):
    pixels = image.getdara()
    characters = "".join([ASCII_CHARS[pixel//25] for pixel in pixels])
    return(characters)

def main(new_width=100):
    #opening source image
    path = input ("Enter pathname for image:\n")
    try:
        image = PIL.Image.open(path)
        #define the image to make it gray then resize the gray output
        new_image_data = pixels_to_ascii(grayify(resize_image(image)))

        #formattin'
        pixel_count = len(new_image_data)
        #'ascii_image' is the head of everything where all grayscales and widths and ratios and whatnot is connected
        ascii_image = "\n".join(new_image_data[i:(i new_width)] for i in range(0, pixel_count, new_width))

        #printing!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
        print(ascii_image)

        #save result
        with open("ascii_image.txt", "w") as f:
            f.write(ascii_image)
        #if no pathname found
    except:
        print(path, "isnt a valid pathname, try another one bro")

    
main()

CodePudding user response：

First of all there is a wrong space between your input function and its argument. Secondly you should consider rewriting your try/except clause as you will run into errors when except is run due to the missing definition of the image variable.