What is the best way to return these 4 integer values?

[Pedroski55]

I have a little Python program to resize pdfs. Works OK for my purposes.

I want to cut it up into functions.

The first function takes the pdf and splits it into jpgs.

The next function opens 1 of the jpgs and should return the values for cropping the pdf. It should just return 4 integers, or 2 tuples (left,top) and (right, bottom)

I don't know how to return these values from this function. What is the best way to return them??

def getSize():
    print('Now getting the optimal size for the pdf ...')
    jpgfiles = os.listdir(pathTojpgs)
    jpgfiles.sort()
    picture = Image.open(pathTojpgs + jpgfiles[0])
    width, height = picture.size
    print('jpg width = ' + str(width) + ' jpg height = ' + str(height))
    answer='NO'
    top = 200
    left=200
    bottom=2000
    right=1500
    im1 = picture.crop((left, top, right, bottom))
    im1 = im1.resize(newsize)
    im1.show()
    answer = input('enter OK if you are happy, otherwise enter NO to try again  ')
    while answer not in 'OK':        
        print('enter new values for top, left, bottom, right')        
        x1 = input('value for left ... ')
        y1 = input('value for top ... ')        
        x2 = input('value for right ... ')
        y2 = input('value for bottom ... ')        
        left = int(x1)
        top = int(y1)        
        right = int(x2)
        bottom = int(y2)
        im1 = picture.crop((left, top, right, bottom))
        im1 = im1.resize(newsize)
        im1.show()
        answer = input('enter OK if you are happy, otherwise enter NO to try again  ')
    return  HOW???? ;

which will then go in this function:

for jpg in jpgfiles:
        picture1 = Image.open(pathTojpgs + jpg)
        im1 = picture1.crop((left, top, right, bottom))
        im1 = im1.resize(newsize)
        output = jpg.split('.')       
        savefilename = output[0] + 'shrunk.jpg'
        im1.save(pathToShrunkjpgs + savefilename)
        print(jpg + ' shrunk and saved to ' + pathToShrunkjpgs) 
    name = output[0]
    jpg2pdf(name) # join the jpgs to a pdf again
    junkjpgs(pathTojpgs) # get rid of the mess
    junkjpgs(pathToShrunkjpgs)

[buran]

return (left, top, right, bottom) # one tuple

or

return((left, top), (right, bottom)) # tuple of tuples

I would define namedtuple in advance, e.g. Point with x and y or Rectangle with left, top, right and bottom. And will return namedtuple

from collections import namedtuple

Rectangle = namedtuple('Rectangle', 'left, top, right, bottom')

def get_int(prompt):
    while True:
        try:
            return int(input(prompt))
        except TypeError:
            print('This is not a valid input. Try again.')


def getSize():
    print('Now getting the optimal size for the pdf ...')
    jpgfiles = os.listdir(pathTojpgs)
    jpgfiles.sort()
    picture = Image.open(pathTojpgs + jpgfiles[0])
    width, height = picture.size
    print('jpg width = ' + str(width) + ' jpg height = ' + str(height))
    crop_rect = Rectangle(left=200, top=200, right=1500, bottom=2000) # you can pass them as positional arguments, but kwargs make it more clear
    while True: 
        im1 = picture.crop(crop_rect) # Fix the error, no need to unpack
        im1 = im1.resize(newsize)
        im1.show()
        answer = input('enter OK if you are happy, otherwise enter NO to try again: ')
        if answer.lower() == 'ok':
            break # break of the loop or you can directly do return  crop_rect and remove the return statement from the end
        print('enter new values for top, left, bottom, right')
        crop_rect = Rectangle(*[get_int(f'Value for {coord}: ') for coord in Rectangle._fields])  
    return crop_rect

I also simplified your function and made another function to guarantee that input is int

[Pedroski55]

Thank you very much, I've never used tuples before, wasn't sure how to handle them!

---

Slight hiccough:

I only changed getSize() by passing it jpgfiles[0]

def getSize(ajpg):
    print('Now getting the optimal size for the pdf ...')    
    picture = Image.open(pathTojpgs + ajpg)
    width, height = picture.size
    print('jpg width = ' + str(width) + ' jpg height = ' + str(height))
    crop_rect = Rectangle(left=200, top=200, right=1500, bottom=2000) # you can pass them as positional arguments, but kwargs make it more clear
    while True: 
        im1 = picture.crop(*crop_rect)
        im1 = im1.resize(newsize)
        im1.show()
        answer = input('enter OK if you are happy, otherwise enter NO to try again: ')
        if answer.lower() == 'ok':
            break # break of the loop or you can directly do return  crop_rect and remove the return statement from the end
        print('enter new values for top, left, bottom, right')
        crop_rect = Rectangle(*[get_int(f'Value for {coord}: ') for coord in Rectangle._fields])  
    return  crop_rect

I tried to use getSize(ajpg) like this:

for file in pdfNames:
    print('splitting ' + file + ' to jpgs ')
    outputName = file.split('.')
    saveFilename = outputName[0]
    splitPDF(file, saveFilename)
    print('pdf split to jpgs!')
    print('now reize the jpgs ... ')
    jpgfiles = os.listdir(pathTojpgs)
    jpgfiles.sort()
    size1 = getSize(jpgfiles[0])
    for jpg in jpgfiles:        
        picture1 = Image.open(pathTojpgs + jpg)
        im1 = picture1.crop(size1)
        im1 = im1.resize(newsize)
        output = jpg.split('.')       
        savefilename = output[0] + 'shrunk.jpg'
        im1.save(pathToShrunkjpgs + savefilename)
        print(jpg + ' shrunk and saved to ' + pathToShrunkjpgs) 
    name = output[0]
    jpg2pdf(name)
    junkjpgs(pathTojpgs)
    junkjpgs(pathToShrunkjpgs)

but getSize(ajpg) is showing this error:

>>> size1 = getSize(jpgfiles[0])
Now getting the optimal size for the pdf ...
jpg width = 1654 jpg height = 2339
Traceback (most recent call last):
File "<pyshell#61>", line 1, in <module>
size1 = getSize(jpgfiles[0])
File "<pyshell#60>", line 8, in getSize
im1 = picture.crop(*crop_rect)
TypeError: crop() takes from 1 to 2 positional arguments but 5 were given
>>>

I can't see the problem, can you please advise?

[buran]

sorry, I overlooked that - you don't need to unpack the tuple when you pass it to crop

        im1 = picture.crop(*crop_rect)

should be

        im1 = picture.crop(crop_rect)

[Pedroski55]

Thanks again!

I stopped yesterday, too long in front of the computer. It's nearly 6am now, I just tried it. Works great!

>>> size1
Rectangle(left=230, top=200, right=1330, bottom=1850)

That should keep the gf. happy!!

Obviously, your code is much more sophisticated than the rubbish I write. I'm still trying to understand it!

Thanks again!