Drop python3.5 support

[yuokada]

Python 3.5 was reached end-of-life in 2020. So we can drop python3.5 support.

• https://www.python.org/downloads/release/python-3510/

[joshthoward]

Hey guys. What is the rationale behind dropping Python 3.5 before Python 2?

From this issue, we get roughly 6x the number of 3.5 downloads compared to 2.7.

[yuokada]

To be honest, I don't have the big reason to drop python3.5 support.
Since python3.5 was reached end-of-life, I sent the pr mechanically

One of the reason why dropping python3.5 support is relationship to dependency libraries.
Pytest has already dropped python3.5 support. So we might be unable to run tests on python 3.5 properly in the near future.
https://pypi.org/project/pytest/

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And also, we can use some functionalities in python 3.6 or later.
https://docs.python.org/3/whatsnew/3.6.html

[electrum]

This seems to also be adding support for newer versions. Can you create a separate PR for that? It should not be controversial (compared to dropping an old version) and we can merge it right away.

[yuokada]

Created
#72

[electrum]

Since this version is working today, I suggest we keep it for now. We can revisit the decision when there is a need, such as wanting to use new syntax or new dependency versions, or if something stops working. Then we can weigh the positive/negative, whereas dropping it now seems to only be a negative.

[yuokada]

@electrum I see. I will close the pr.

[findepi]

Hey guys. What is the rationale behind dropping Python 3.5 before Python 2?

From this issue, we get roughly 6x the number of 3.5 downloads compared to 2.7.

@joshthoward
there are two reasons

• in my not so intensive python development in past 2-3 years i've witnessed problems present in 3.5 and fixed in 3.6. Enough for me to think there is little value supporting Python 3.5 (this is based on memory though)
  • on the other hand, python 2.7 is very solid (even though no longer supported)
• there is clean upgrade path for users from Python 3.5 to 3.6+
  • this is a big difference between 3.5 and 2.7

i did not know the download numbers when approving.
Knowing the numbers, I would still consider removing 3.5 support for the reasons outlined above, but i can be perhaps convinced to think differently.