Converting images to PDF. Final file has blank pages before and after.

[MRAB]

On 2020-12-03 03:32, Michael Baca wrote:
> On Monday, November 30, 2020 at 7:15:37 PM UTC-7, MRAB wrote:
>> On 2020-12-01 01:20, Michael Baca wrote: 
>> > Hello, new to the group, rather new to programming. 
>> > 
>> > I'm writing a program that takes images and converts them into PDF's. It works after quite a few days of trying, however the final file has a blank page inserted before and after each page containing the images. 
>> > 
>> > This uses FPDF to do the conversion. I've been up and down trying to figure out where I'm adding an extra page, so it might be an FPDF issue. 
>> > 
>> > def multi_convert(pdf_Filename, file_path): 
>> > if (dir): 
>> > file_list = [] 
>> > print(""), print("") 
>> > print("Converting... This may take awhile depending on the number of images.") 
>> > 
>> > for entry in os.scandir(file_path): 
>> > if (entry.path.endswith(".jpg") or entry.path.endswith(".png")) and entry.is_file(): 
>> > file_list.append(entry.path) 
>> > else: 
>> > print("Error: ") 
>> > print("Invalid Directory - {}", dir) 
>> > cover = Image.open(str(file_list[0])) 
>> > width, height = cover.size 
>> > 
>> > pdf = FPDF(unit="pt", format=[width, height]) 
>> > 
>> > for page in file_list: 
>> > pdf.add_page() 
>> > pdf.image(str(page)) 
>> > 
>> > pdf.output(file_path + pdf_Filename + ".pdf", "F") 
>> > exit() 
>> >
>> It says in the documentation for the .image method: 
>> 
>> """ 
>> x: 
>> 
>> Abscissa of the upper-left corner. If not specified or equal to None, 
>> the current abscissa is used (version 1.7.1 and up). 
>> 
>> y: 
>> 
>> Ordinate of the upper-left corner. If not specified or equal to None, 
>> the current ordinate is used; moreover, a page break is triggered first 
>> if necessary (in case automatic page breaking is enabled) and, after the 
>> call, the current ordinate is moved to the bottom of the image (version 
>> 1.7.1 and up). 
>> """ 
>> 
>> In other words, you're not specifying where the top-left corner of the 
>> image should go, so it's putting it at the current position, wherever 
>> that is, and it's responding to the positioning by inserting additional 
>> pages. 
>> 
>> The solution is to specify the images' positions, and, perhaps, also 
>> their sizes, if necessary. 
>> 
>> By the way, why doesn't the function end with "exit()"? That'll make it 
>> exit the Python completely; rarely a good idea.
> 
> Thank you very much for the help. That makes sense, as I remember reading about the image placement, but I didn't think it mattered. My use is very simple, I occasionally need to covert images into to PDF's and this makes it easier than going online. So I figured it was okay to leave that out. I need to go back and read the  manual some more.
> 
> It's a CLI program, it takes a few different arguments and when it's done it just returns to the shell. That's why I have the exit() where I do. Is there a better/safer way to exit the program?
> 
It's best if a function just returns to its caller. That's what you'd 
expect a function to do, and it's a good practice to follow because it 
reduces the number of unexpected "surprises" in the long term or if you 
come back to the code much later.