This took a little longer than it should to figure out..
For what ever reason install pygal using pip on my debian stretch yielded this error.
pi@tomrpi3:~ $ pip install pygal
Collecting pygal
Exception:
Traceback (most recent call last):
File “/usr/lib/python2.7/dist-packages/pip/basecommand.py”, line 215, in main
status = self.run(options, args)
File “/usr/lib/python2.7/dist-packages/pip/commands/install.py”, line 353, in run
wb.build(autobuilding=True)
File “/usr/lib/python2.7/dist-packages/pip/wheel.py”, line 749, in build
self.requirement_set.prepare_files(self.finder)
File “/usr/lib/python2.7/dist-packages/pip/req/req_set.py”, line 380, in prepare_files
ignore_dependencies=self.ignore_dependencies))
File “/usr/lib/python2.7/dist-packages/pip/req/req_set.py”, line 554, in _prepare_file
require_hashes
File “/usr/lib/python2.7/dist-packages/pip/req/req_install.py”, line 278, in populate_link
self.link = finder.find_requirement(self, upgrade)
File “/usr/lib/python2.7/dist-packages/pip/index.py”, line 465, in find_requirement
all_candidates = self.find_all_candidates(req.name)
File “/usr/lib/python2.7/dist-packages/pip/index.py”, line 423, in find_all_candidates
for page in self._get_pages(url_locations, project_name):
File “/usr/lib/python2.7/dist-packages/pip/index.py”, line 568, in _get_pages
page = self._get_page(location)
File “/usr/lib/python2.7/dist-packages/pip/index.py”, line 683, in _get_page
return HTMLPage.get_page(link, session=self.session)
File “/usr/lib/python2.7/dist-packages/pip/index.py”, line 792, in get_page
“Cache-Control”: “max-age=600”,
File “/usr/share/python-wheels/requests-2.12.4-py2.py3-none-any.whl/requests/sessions.py”, line 501, in get
return self.request(‘GET’, url, **kwargs)
File “/usr/lib/python2.7/dist-packages/pip/download.py”, line 386, in request
return super(PipSession, self).request(method, url, *args, **kwargs)
File “/usr/share/python-wheels/requests-2.12.4-py2.py3-none-any.whl/requests/sessions.py”, line 488, in request
resp = self.send(prep, **send_kwargs)
File “/usr/share/python-wheels/requests-2.12.4-py2.py3-none-any.whl/requests/sessions.py”, line 609, in send
r = adapter.send(request, **kwargs)
File “/usr/share/python-wheels/CacheControl-0.11.7-py2.py3-none-any.whl/cachecontrol/adapter.py”, line 47, in send
resp = super(CacheControlAdapter, self).send(request, **kw)
File “/usr/share/python-wheels/requests-2.12.4-py2.py3-none-any.whl/requests/adapters.py”, line 423, in send
timeout=timeout
File “/usr/share/python-wheels/urllib3-1.19.1-py2.py3-none-any.whl/urllib3/connectionpool.py”, line 643, in urlopen
_stacktrace=sys.exc_info()[2])
File “/usr/share/python-wheels/urllib3-1.19.1-py2.py3-none-any.whl/urllib3/util/retry.py”, line 315, in increment
total -= 1
TypeError: unsupported operand type(s) for -=: ‘Retry’ and ‘int’
I get the impression that this might pip in the repo’s might not be at the correct version.
https://stackoverflow.com/questions/37495375/python-pip-install-throws-typeerror-unsupported-operand-types-for-retry
I didn’t want to go down that route, but I did find another option here:
https://www.howtoinstall.co/en/debian/stretch/python-pygal
sudo apt-get update
sudo apt-get install python-pygal