只要點兩下，就能將input資料夾內所有PDF進行容量壓縮

系列文章：
01.python 不管何時何地，只要點兩下，資料夾內的所有pdf都會合併成一個pdf
https://skjhcreator.blogspot.com/2022/06/pythonpdfpdf.html
02.python 只要點兩下，分別對各資料夾內的pdf合併，合併後的檔名要讓人知道來自哪個資料夾 
https://skjhcreator.blogspot.com/2022/06/python-pdf.html
03. 只要點兩下，就能將一堆的Doc與Docx 轉成 PDF
03.https://skjhcreator.blogspot.com/2023/05/docdocx-pdf.html
04.只要點兩下，就能將一堆的JPG轉成一個PDF，並以JPG所在的資料夾名稱為PDF的檔名
04.https://skjhcreator.blogspot.com/2023/06/jpgpdfjpgpdf.html
05.只要點兩下，就能將放進input的一堆PDF轉成各自的WORD
05.https://skjhcreator.blogspot.com/2023/10/inputpdfword.html
06.只要點兩下，就能將放進input的一堆PDF轉成在ouput資料夾內的各自的WORD 
06.https://skjhcreator.blogspot.com/2023/10/inputpdfouputword.html
07.只要點兩下，就能夠將InputAndOutput資料夾底下的子子孫孫資料夾內所有Word通通轉成PDF
07.https://skjhcreator.blogspot.com/2024/09/word-word-pdf.html
08.只要點兩下，就可以將資料夾input內的所有Word通通轉成一個PDF
08.https://skjhcreator.blogspot.com/2025/07/inputwordpdf.html
09.只要點兩下兩次，就能依照設定拆分指定PDF頁數並合併成設定好的一個PDF
09.https://skjhcreator.blogspot.com/2025/09/pdfpdf.html
10.只要點兩下，就能將input資料夾內所有PDF進行容量壓縮
10.https://skjhcreator.blogspot.com/2026/04/inputpdf.html

Just double-click to compress all PDFs in the input folder.

        最近要上傳一大堆的PDF，常常因為PDF內的照片未經壓縮，導致整體容量過大。上傳時又因容量過大，導致無法上傳。上傳網站要求多少容量內的PDF才能上傳。問題是PDF不是我做的，偏偏又要發回或通知原主，要做PDF壓縮，才能上傳。如此的一來一往，浪費很多時間。能不能有個程式，讓我點個兩下就能將這些PDF進行壓縮，而不用再跟原主溝通？

        Recently, I’ve had to upload a large number of PDFs, but they’re often too big because the images inside them haven’t been compressed. As a result, the files exceed the upload size limit and can’t be uploaded. The website requires PDFs to be under a certain size, but the problem is that I didn’t create these PDFs. I end up having to send them back or notify the original creator to compress them before I can upload them. This back-and-forth wastes a lot of time.

        Is there a program that would let me simply double-click and compress these PDFs myself, without needing to communicate with the original creator?

方法：Python + Ghostscript
一、下載與安裝 Ghostscript
到 https://www.ghostscript.com/download/gsdnld.html 下載後，點兩下進行安裝

二、Python 程式碼

檔案：pyPdfCompress.py

檔案內容：

import os

import subprocess

INPUT_DIR = "input"

OUTPUT_DIR = "output"

GS_COMMAND = "gswin64c"  # Windows 用這個（如果不行可改 "gs"）

QUALITY = "ebook"  # screen / ebook / printer / prepress

quality_settings = {

    "screen": "/screen",

    "ebook": "/ebook",

    "printer": "/printer",

    "prepress": "/prepress"

}

def compress_pdf(input_path, output_path):

    cmd = [

        GS_COMMAND,

        "-sDEVICE=pdfwrite",

        "-dCompatibilityLevel=1.4",

        f"-dPDFSETTINGS={quality_settings.get(QUALITY, '/ebook')}",

        "-dNOPAUSE",

        "-dQUIET",

        "-dBATCH",

        f"-sOutputFile={output_path}",

        input_path

    ]

    subprocess.run(cmd, check=True)

def main():

    if not os.path.exists(OUTPUT_DIR):

        os.makedirs(OUTPUT_DIR)

    files = [f for f in os.listdir(INPUT_DIR) if f.lower().endswith(".pdf")]

    if not files:

        print("input 資料夾內沒有 PDF")

        return

    for file in files:

        input_path = os.path.join(INPUT_DIR, file)

        output_path = os.path.join(OUTPUT_DIR, file)

        try:

            compress_pdf(input_path, output_path)

            original_size = os.path.getsize(input_path) / 1024

            compressed_size = os.path.getsize(output_path) / 1024

            print(f"✔ {file}")

            print(f"   原始: {original_size:.2f} KB")

            print(f"   壓縮: {compressed_size:.2f} KB")

            print(f"   減少: {original_size - compressed_size:.2f} KB\n")

        except Exception as e:

            print(f"✖ 失敗: {file}")

            print(e)

if __name__ == "__main__":

    main()