Convert a pdf file to refined text so that Google Play Books can read out

ocr_pdf.py

from __future__ import print_function
import httplib2
import os
import io

from apiclient import discovery
from oauth2client import client
from oauth2client import tools
from oauth2client.file import Storage
from apiclient.http import MediaFileUpload, MediaIoBaseDownload

import PyPDF2

try:
    import argparse
    flags = argparse.ArgumentParser(parents=[tools.argparser]).parse_args()
except ImportError:
    flags = None

# If modifying these scopes, delete your previously saved credentials
# at ~/.credentials/drive-python-quickstart.json
SCOPES = 'https://www.googleapis.com/auth/drive'
CLIENT_SECRET_FILE = 'credentials.json'
APPLICATION_NAME = 'Drive API Python Quickstart'


def get_credentials():
    """Gets valid user credentials from storage.

    If nothing has been stored, or if the stored credentials are invalid,
    the OAuth2 flow is completed to obtain the new credentials.

    Returns:
        Credentials, the obtained credential.
    """
    credential_path = os.path.join("./", CLIENT_SECRET_FILE)
    store = Storage(credential_path)
    credentials = store.get()
    if not credentials or credentials.invalid:
        flow = client.flow_from_clientsecrets(CLIENT_SECRET_FILE, SCOPES)
        flow.user_agent = APPLICATION_NAME
        if flags:
            credentials = tools.run_flow(flow, store, flags)
        else:  # Needed only for compatibility with Python 2.6
            credentials = tools.run(flow, store)
        print('Storing credentials to ' + credential_path)
    return credentials


def main(imgfile):
    credentials = get_credentials()
    http = credentials.authorize(httplib2.Http())
    service = discovery.build('drive', 'v3', http=http)

    txtfile = "{}.txt".format(os.path.splitext(imgfile)[0])
    
    mime = 'application/vnd.google-apps.document'
    res = service.files().create(
        body={
            'name': imgfile,
            'mimeType': mime
        },
        media_body=MediaFileUpload(imgfile, mimetype=mime, resumable=True)
    ).execute()

    downloader = MediaIoBaseDownload(
        io.FileIO(txtfile, 'wb'),
        service.files().export_media(fileId=res['id'], mimeType="text/plain")
    )
    done = False
    while done is False:
        status, done = downloader.next_chunk()

    service.files().delete(fileId=res['id']).execute()
    print("Done.")

def split_pdf(file_name):
    base_name = os.path.splitext(file_name)[0]
    reader1 = PyPDF2.PdfFileReader(file_name)
    num_pages = reader1.numPages

    _output = list()
    for num, init_page in enumerate(range(1, num_pages, 80)):
        print(init_page)
        merger = PyPDF2.PdfFileMerger()

        if num_pages < init_page + 79:
            last_page = num_pages
        else:
            last_page = init_page + 79
        merger.append(file_name, 
                    pages=PyPDF2.pagerange.PageRange('{}:{}'.format(init_page, last_page)))
        output_file = '{}_0{}.pdf'.format(base_name, num) 
        merger.write(output_file)
        merger.close()
        _output.append(output_file)
    return _output

def combine_file(files):
    _tmp = list()
    for _ in files:
        with open(_) as f:
            _tmp += f.readlines()
    file_name = "{}.txt".format(str(os.path.splitext(_)[0]).split("_")[0])
    with open(file_name, "w", encoding="utf-8") as f:
        f.writelines(_tmp)
    return file_name

def refine_text(input_file):
    with open(input_file) as f:
        data = f.readlines()

    whole = list()
    new_data = list()
    for _ in data:
        _ = _.replace(" ", "")
        if (_[-2] == "。") or (_[-2] == "」"):
            new_data.append(_[:-1])
            whole.append(''.join(new_data)+'\n')
            new_data = list()
        else:
            new_data.append(_[:-1])
    output_file = "{}_refined.txt".format(os.path.splitext(input_file)[0])
    with open(output_file, "w", encoding="utf-8") as f:
        f.writelines(whole)

if __name__ == '__main__':
    file_names = split_pdf("なぜ私だけが苦しむのかトリム.pdf")
    for _ in file_names:
        main(_)
    file_names = ["{}.txt".format(os.path.splitext(_)[0]) for _ in file_names]
    output_name = combine_file(file_names)
    refine_text(output_name)

Listening an audio book during a long drive is of interest. Cut the books, scan, then convert it to .epub.

Wrote this code so that I can convert pdf file to text file using Google Drive OCR. This code allows me to listen audio book that I cut and scanned.