fixs importlib.{metadata,resource} for new python version (#840)

Signed-off-by: Marco Genasci <fedeliallalinea@gmail.com>

setup.cfg

@@ -49,8 +49,8 @@ install_requires =
     cffi>=1.9.1  # must be a setup and install requirement
     coloredlogs>=14.0  # strictly optional
     img2pdf>=0.3.0,<0.5  # pure Python
-    importlib-metadata>=4  # until Python 3.8
-    importlib-resources>=5  # until Python 3.9
+    importlib-metadata>=4;python_version<'3.8'  # until Python 3.8
+    importlib-resources>=5;python_version<'3.9'  # until Python 3.9
     pdfminer.six!=20200720,>=20191110,<=20201018
     pikepdf>=2.10.0
     pikepdf<3;implementation_name=="pypy" and python_version=='3.6'
@@ -112,4 +112,4 @@ ignore =
 ignore = D203,F401,W503,E501,E203,F841
 exclude = .git,__pycache__,docs/conf.py,build,dist,.venv,.venvpp,.eggs,tmp,src/ocrmypdf/lib/
 max-complexity = 10
-max-line-length = 100
+max-line-length = 100

src/ocrmypdf/_version.py

@@ -5,7 +5,10 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 
-from importlib_metadata import version as _package_version
+try:
+    from importlib_metadata import version as _package_version
+except ImportError:
+    from importlib.metadata import version as _package_version
 
 PROGRAM_NAME = 'ocrmypdf'
 

src/ocrmypdf/pdfa.py

@@ -13,7 +13,10 @@ import base64
 from pathlib import Path
 from typing import Dict, Iterator, Union
 
-import importlib_resources
+try:
+    from importlib_resources import read_binary
+except ImportError:
+    from importlib.resources import read_binary
 import pikepdf
 import pkg_resources  # deprecated
 
@@ -104,7 +107,7 @@ def generate_pdfa_ps(target_filename: Path, icc: str = 'sRGB'):
     if icc != 'sRGB':
         raise NotImplementedError("Only supporting sRGB")
 
-    bytes_icc_profile = importlib_resources.read_binary(
+    bytes_icc_profile = read_binary(
         'ocrmypdf.data', SRGB_ICC_PROFILE_NAME
     )
     ps = '\n'.join(_make_postscript(icc, bytes_icc_profile, 3))