Getting errors reading pdf files using pdfminer

Question

I am trying to read pdf files with this code on Ubuntu

from pdfminer.pdfinterp import PDFResourceManager, PDFPageInterpreter
from pdfminer.pdfpage import PDFPage
from pdfminer.converter import TextConverter
from pdfminer.layout import LAParams
from cStringIO import StringIO

def pdf_to_text(pdfname):
    # PDFMiner boilerplate
    rsrcmgr = PDFResourceManager()
    sio = StringIO()
    device = TextConverter(rsrcmgr, sio, codec='utf-8', laparams=LAParams())
    interpreter = PDFPageInterpreter(rsrcmgr, device)
      # get text from file
    fp = file(pdfname, 'rb')
    for page in PDFPage.get_pages(fp):
        interpreter.process_page(page)
    fp.close()
      # Get text from StringIO
    text = sio.getvalue()
      # close objects
    device.close()
    sio.close()

    return text

I have also installed pdfminer

$ sudo apt-get install -y python3-pdfminer
Reading package lists... Done
Building dependency tree       
Reading state information... Done
python3-pdfminer is already the newest version (20191020+dfsg-2).
python3-pdfminer set to manually installed.
0 upgraded, 0 newly installed, 0 to remove and 72 not upgraded.

When I run the code with pdfminer I get following errors

ModuleNotFoundError: No module named 'pdfminer.pdfinterp'

And also

ModuleNotFoundError: No module named 'pdfminer.psparser'
ModuleNotFoundError: No module named 'pdfminer.converter'
ModuleNotFoundError: No module named 'pdfminer.layout'

How to install pdfminer to remove above errors?