从PDF文件中提取关键字

Question

我想从PDF文件中提取关键字以与弹性搜索一起在我的网站上使用。代码运行正常，但是输出（关键字）都是不可读的东西。

import PyPDF2
import textract
import nltk
nltk.download('punkt')
from nltk.tokenize import word_tokenize
from nltk.corpus import stopwords

# This function will extract and return the pdf file text content.
def extractPdfText(filePath=''):
    # Open the pdf file in read binary mode.
    fileObject = open(filePath, 'rb')
    # Create a pdf reader .
    pdfFileReader = PyPDF2.PdfFileReader(fileObject)
    # Get total pdf page number.
    totalPageNumber = pdfFileReader.numPages
    # Print pdf total page number.
    print('This pdf file contains totally ' + str(totalPageNumber) + ' pages.')
    currentPageNumber = 0
    text = ''
    # Loop in all the pdf pages.
    while(currentPageNumber < totalPageNumber ):

        # Get the specified pdf page object.
        pdfPage = pdfFileReader.getPage(currentPageNumber)
        # Get pdf page text.
        text = text + pdfPage.extractText()
        # Process next page.
        currentPageNumber += 1
    if(text == ''):
        # If can not extract text then use ocr lib to extract the scanned pdf file.
        text = textract.process(filePath, method='tesseract', encoding='utf-8')
    return text

# This function will remove all stop words and punctuations in the text and return a list of keywords.
def extractKeywords(text):
    # Split the text words into tokens
    wordTokens = word_tokenize(text)
    # Remove blow punctuation in the list.
    punctuations = ['(',')',';',':','[',']',',']
    # Get all stop words in english.
    stopWords = stopwords.words('english')
    # Below list comprehension will return only keywords tha are not in stop words and  punctuations
    keywords = [word for word in wordTokens if not word in stopWords and not word in punctuations]
    return keywords

if __name__ == '__main__': 
    pdfFilePath = '/home/bjorn/Downloads/Engelsk_stil.pdf'
    pdfText = extractPdfText(pdfFilePath)
    print('There are ' + str(pdfText.__len__()) + ' word in the pdf file.')
    #print(pdfText)
    keywords = extractKeywords(pdfText)
    print('There are ' + str(keywords.__len__()) + ' keyword in the pdf file.')
    print(keywords)

它应该打印所有关键字，但最终不可读

  

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