如何用Python从两列pdf中提取文本？

import PyPDF2

pdf1 = open('file1.pdf', 'rb')
pdf2 = open('file2.pdf', 'rb')

reader1 = PyPDF2.PdfReader(pdf1)
reader2 = PyPDF2.PdfReader(pdf2)

def extract_text(reader):
    text = ''
    for page in reader.pages:
        text += page.extract_text()
    return text

text1 = extract_text(reader1)
text2 = extract_text(reader2)

pdf1.close()
pdf2.close()