Traceback (most recent call last):


 "simple_app.py", line 3, in <module>

from escpos import *
AttributeError: module 'escpos' has no attribute 'constants'

Traceback (most recent call last):


 "<pyshell#9>", line 1, in <module>

r.html.render()


 "C:\Python36\lib\site-packages\requests_html.py", line 583, in render

content, result, page = self.session.loop.run_until_complete(_async_render(url=self.url, script=script, sleep=sleep, wait=wait, content=self.html, reload=reload, scrolldown=scrolldown, timeout=timeout, keep_page=keep_page))


 "C:\Python36\lib\asyncio\base_events.py", line 468, in run_until_complete

return future.result()


 "C:\Python36\lib\site-packages\requests_html.py", line 564, in _async_render

content = await page.content()


 "C:\Python36\lib\site-packages\pyppeteer\page.py", line 780, in content

return await frame.content()


 "C:\Python36\lib\site-packages\pyppeteer\frame_manager.py", line 379, in content

'''.strip())


 "C:\Python36\lib\site-packages\pyppeteer\frame_manager.py", line 295, in evaluate

pageFunction, *args, force_expr=force_expr)


 "C:\Python36\lib\site-packages\pyppeteer\execution_context.py", line 55, in evaluate

pageFunction, *args, force_expr=force_expr)


 "C:\Python36\lib\site-packages\pyppeteer\execution_context.py", line 109, in evaluateHandle

_rewriteError(e)


 "C:\Python36\lib\site-packages\pyppeteer\execution_context.py", line 238, in _rewriteError

raise type(error)(msg)
pyppeteer.errors.NetworkError: Execution context was destroyed, most likely because of a navigation.
