这个Python程序的主要功能是从PDF文件中提取文本和图片，并根据指定的顺序重新排序图片后生成一个新的PDF文件。以下是对每个主要功能模块的详细介绍：

1. 提取PDF中的文本

```python
def extract_text_from_pdf(pdf_path):
"""Extract text from the PDF file."""
with pdfplumber.open(pdf_path) as pdf:
text = ''
for page in pdf.pages:
text += page.extract_text()
return text
该函数使用`pdfplumber`库打开PDF文件，并逐页提取文本内

2. 提取PDF中的图片

```python
def extract_images_from_pdf(pdf_path):
"""Extract images from the PDF file and save them as separate files."""
images = []
with pdfplumber.open(pdf_path) as pdf:
for i, page in enumerate(pdf.pages):
for image in page.images:
bbox = (image['x0'], image['top'], image['x1'], image['bottom'])
page_image = page.to_image()
cropped_image = page_image.crop(bbox)
image_path = f"image_{i}_{image['index']}.png"
cropped_image.save(image_path)
images.append(image_path)
return images