環境

Windows10
Python3.6
Anaconda

発生している問題

PDFMinerを使ってPDFから文章を抜き出そうとするとWarningが出ます。

Python
1from pdfminer.pdfparser import PDFParser
2from pdfminer.pdfparser import PDFDocument
3from pdfminer.pdfinterp import PDFResourceManager, PDFPageInterpreter
4from pdfminer.layout import LAParams
5from pdfminer.converter import PDFPageAggregator
6
7fp = open(pdf_file, 'rb')
8
9parser = PDFParser(fp)
10document = PDFDocument()
11parser.set_document(document)
12
13document.set_parser(parser)
14rsrcmgr = PDFResourceManager()
15laparams = LAParams()
16device = PDFPageAggregator(rsrcmgr, laparams=laparams)
17interpreter = PDFPageInterpreter(rsrcmgr, device)
18pages = list(document.get_pages())
19page_1 = pages[0]
20interpreter.process_page(page_1)
21layout = device.get_result()

これを実行すると次のような警告が出ます。

Python
1WARNING:root:Cannot locate objid=725
2WARNING:root:Cannot locate objid=728
3WARNING:pdfminer.converter:undefined: <PDFType1Font: basefont='LDDDEK+MTSY'>, 2
4WARNING:pdfminer.converter:undefined: <PDFType1Font: basefont='LDDDEK+MTSY'>, 3
5WARNING:pdfminer.converter:undefined: <PDFType1Font: basefont='LDDDEK+MTSY'>, 2
6WARNING:pdfminer.converter:undefined: <PDFType1Font: basefont='LDDDEK+MTSY'>, 3
7WARNING:pdfminer.converter:undefined: <PDFType1Font: basefont='LDDDEK+MTSY'>, 2
8WARNING:pdfminer.converter:undefined: <PDFType1Font: basefont='LDDDEK+MTSY'>, 3