如何让我的代码用我提供的数据实际生成一个Json字典。代码运行良好，但没有任何输出

Question

我可以从PDF文件中提取文本，现在我想将这些数据提取到json字典中。代码运行，但不提供任何输出。我错过了什么？我应该用文本提取器创建一个不同的类，然后用json转换器创建一个新类吗？你知道吗

import io
import os
import json
from pdfminer.converter import TextConverter
from pdfminer.pdfinterp import PDFPageInterpreter
from pdfminer.pdfinterp import PDFResourceManager
from pdfminer.pdfpage import PDFPage


def extract_text_by_page(pdf_path):
    with open(pdf_path, 'rb') as fh:
        for page in PDFPage.get_pages(fh, 
                                      caching=True,
                                      check_extractable=True):
            resource_manager = PDFResourceManager() # #creates a resource manager instance
            fake_file_handle = io.StringIO()    #creates a file like object 
            converter = TextConverter(resource_manager, fake_file_handle) #creates a text converter 'loads all text disfiguratevetly'
            page_interpreter = PDFPageInterpreter(resource_manager, converter)
            page_interpreter.process_page(page)
            text = fake_file_handle.getvalue() #gets all the data regardles its position 
            yield text

            converter.close()
            fake_file_handle.close()
def extract_text(pdf_path):                         # extracts the text figuratevetly, this means all the charactaers in the file will be extracted
    for page in extract_text_by_page(pdf_path):
        print(page)
        print()
if __name__ == '__main__':
print(extract_text('cpu-api.pdf'))



def export_as_json(pdf_path, json_path):
    filename = os.path.splitext(os.path.basename(pdf_path))[0]
    data = {'Filename': filename}
    data['Pages'] = []
    counter = 1
    for page in extract_text_by_page(pdf_path):
        text = page[0:200]
        page = {'Page_{}'.format(counter): text}
        data['Pages'].append(page)
        counter += 1
    with open(json_path, 'w') as fh:
    json.dump(data, fh)
if __name__ == '__main__':
    pdf_path = 'cpu-api.pdf'
    json_path = 'cpu-api.json'
    export_as_json(pdf_path, json_path)