Bump minimum python version to 3.6

ajtowns commented at 5:26 am on July 13, 2020: member

Python 3.5 has reached end-of-life as of September 2020, and 3.6 has some moderately nice features:

f'x = {x}' as an alternative to 'x = {}'.format(x) format strings (cf #13718 (comment))
underscore separators for large numbers, like 1_234_567
improvements to async
improvements to typing module

Note that 3.6 is not available in xenial (16.04), but is available in bionic (18.04), while focal (20.04) has 3.8. CentOS 7 and 8 have 3.6.8, Debian stable has 3.7.3, and gentoo and arch already had 3.6 and 3.7 in 2018.

fanquake added the label Build system on Jul 13, 2020

MarcoFalke commented at 5:40 am on July 13, 2020: member

review ACK, but I am not sure if we need to push this into the upcoming release. Is there any reason this can’t wait 3.5 months? While xenial has a c++17 compiler, but lacks a c++17 compatible stdlib, xenial will die anyway. No strong opinion, though.

Might need to update the travis yaml python linter version?

DrahtBot commented at 5:51 am on July 13, 2020: member

The following sections might be updated with supplementary metadata relevant to reviewers and maintainers.

Conflicts

Reviewers, this pull request conflicts with the following ones:

#19179 (ci: Run ci configs on cirrus by MarcoFalke)

If you consider this pull request important, please also help to review the conflicting pull requests. Ideally, start with the one that should be merged first.

ajtowns force-pushed on Jul 13, 2020

ajtowns commented at 6:12 am on July 13, 2020: member

No objection to letting it wait; mostly just thought it made more sense to do a PR directly than open a “python 3.5 is nearing eol” issue.

practicalswift commented at 9:23 am on July 13, 2020: contributor

Concept ACK: alive is better than end-of-life

MarcoFalke added this to the milestone 0.21.0 on Jul 13, 2020

MarcoFalke removed this from the milestone 0.21.0 on Jul 13, 2020

MarcoFalke added this to the milestone 0.22.0 on Jul 13, 2020

MarcoFalke commented at 9:40 am on July 13, 2020: member

Assigned 0.22.0 milestone with proposed merge date of Nov 1st.

If python 3.6 is needed to simplify mypy, then it can be merged sooner #19389 (comment)

jnewbery commented at 10:31 am on July 13, 2020: member

Concept ACK

Sjors commented at 3:41 pm on July 14, 2020: member

Concept ACK. No strong preference on when, but having it coincide with our C++17 bump makes sense.

in .python-version:1 in 2b53176fd0 outdated

0@@ -1 +1 @@
1-3.5.6
2+3.6.5

Sjors commented at 3:42 pm on July 14, 2020:

This is only used by PyEnv, which can install the more modern 3.6.11 just as well.

ajtowns commented at 5:55 pm on October 1, 2020:

updated to 3.6.12 released in August

Sjors commented at 6:09 pm on October 1, 2020:

Python 3.6.12 is not yet availabe via Homebrew’s PyEnv, but that should be fixed by the time this lands. I just manually switched to 3.6.11 for testing. https://github.com/pyenv/pyenv/pull/1680#issuecomment-701478171

laanwj commented at 1:49 pm on July 15, 2020: member

I like Python 3.6’s improvements a lot,1 concept ACK if/when the Linux distributions we support building on have it.

in ci/test/00_setup_env_native_nowallet.sh:10 in 2b53176fd0 outdated

 6@@ -7,8 +7,8 @@
 7 export LC_ALL=C.UTF-8
 8 
 9 export CONTAINER_NAME=ci_native_nowallet
10-export DOCKER_NAME_TAG=ubuntu:16.04  # Use xenial to have one config run the tests in python3.5, see doc/dependencies.md
11-export PACKAGES="python3-zmq clang-3.8 llvm-3.8"  # Use clang-3.8 to test C++11 compatibility, see doc/dependencies.md
12+export DOCKER_NAME_TAG=ubuntu:18.04  # Use bionic to have one config run the tests in python3.6, see doc/dependencies.md (3.6 is not available in xenial/16.04)

MarcoFalke commented at 4:47 am on July 16, 2020:

the travis yaml will need to be updated as well (name of the config)

ajtowns commented at 5:55 pm on October 1, 2020:

updated travis yaml

troygiorshev commented at 6:22 pm on July 16, 2020: contributor

Concept ACK

If python 3.6 is needed to simplify mypy, then it can be merged sooner #19389 (comment)

From what I can tell right now, I don’t think this will be the case. I think we’ll be ok with 3.5.

fjahr commented at 9:05 am on July 17, 2020: member

tested ACK 2b53176fd0a2d594ee7833397d3b32c59d1bbae0

Agree this can wait a bit and be done with c++17.

fanquake commented at 6:46 am on July 28, 2020: member

Concept ACK. No mention of 3.6+ related typing improvements in the op, which is probably what I’m most interested in. I wouldn’t be overly concerned about CentOS 7 or Xenial support here.

DrahtBot added the label Needs rebase on Aug 5, 2020

theStack commented at 0:42 am on September 6, 2020: member

Strong concept ACK (no need to rush though, as others already stated doing this along with the C++17 bump seems reasonable).

kristapsk commented at 6:27 pm on September 7, 2020: contributor

Concept ACK

MarcoFalke commented at 7:17 am on October 1, 2020: member

@ajtowns Are you still working on this? Would be good to rebase and address the feedback

ajtowns force-pushed on Oct 1, 2020

Sjors commented at 6:18 pm on October 1, 2020: member

tACK ef0b760 on macOS 10.15.7

DrahtBot removed the label Needs rebase on Oct 1, 2020

kristapsk commented at 7:07 pm on October 1, 2020: contributor

Use f'{x}' for string formatting in preference to '{}'.format(x) or '%s' % x.

This PR changes this in test/functional/feature_block.py, but there are other places where .format is still used, shouldn’t it be changed everywhere then?

Also, maybe some linter script could be added that checks .py files for this?

But probably that’s out of scope of this PR and can be done in follow-up PR(s).

ajtowns commented at 7:41 pm on October 1, 2020: member

Use f'{x}' for string formatting in preference to '{}'.format(x) or '%s' % x.

This PR changes this in test/functional/feature_block.py, but there are other places where .format is still used, shouldn’t it be changed everywhere then?

It’s changed there so that CI tests that it works (eg, failing if an older version of python is being used) and as an example for what the style looks like. General policy is to update code to new style guidelines only when the code is touched for other reasons, so really even doing that is pushing it :)

in ci/test/00_setup_env_native_nowallet.sh:14 in ef0b7604cb outdated

12+export DOCKER_NAME_TAG=ubuntu:18.04  # Use bionic to have one config run the tests in python3.6, see doc/dependencies.md (3.6 is not available in xenial/16.04)
13+export PACKAGES="python3-zmq clang-3.9 llvm-3.9"  # Use clang-3.9 to test C++11 compatibility, see doc/dependencies.md (3.8 is not available in bionic)
14 export DEP_OPTS="NO_WALLET=1"
15 export GOAL="install"
16-export BITCOIN_CONFIG="--enable-glibc-back-compat --enable-reduce-exports CC=clang-3.8 CXX=clang++-3.8 --with-boost-process"
17+export BITCOIN_CONFIG="--enable-glibc-back-compat --enable-reduce-exports CC=clang-3.8 CXX=clang++-3.9 --with-boost-process"

fanquake commented at 5:51 am on October 2, 2020:

0export BITCOIN_CONFIG="--enable-glibc-back-compat --enable-reduce-exports CC=clang-3.9 CXX=clang++-3.9 --with-boost-process"

MarcoFalke commented at 9:54 am on October 16, 2020:

@ajtowns Mind fixing the typo, so that ci passes here?

ajtowns commented at 2:38 pm on October 17, 2020:

Thought I’d done that already… Done now anyway

practicalswift commented at 1:51 pm on October 16, 2020: contributor

ACK modulo fix for CI failure :)

ajtowns force-pushed on Oct 17, 2020

MarcoFalke commented at 9:21 am on October 19, 2020: member

ACK 9bc4cdf0beb95072ab33b418349df8f7217b329d

for 0.22

in .travis.yml:86 in ea39d8bc9e outdated

109@@ -110,7 +110,7 @@ jobs:
110         FILE_ENV="./ci/test/00_setup_env_native_multiprocess.sh"
111 
112     - stage: test
113-      name: 'x86_64 Linux  [GOAL: install]  [xenial]  [no wallet]'
114+      name: 'x86_64 Linux  [GOAL: install]  [bionic]  [no wallet]'

MarcoFalke commented at 7:54 pm on November 4, 2020:

in commit ea39d8bc9e1b7c23486abc5b28a20d4660fe93dd:

Sorry this needs a rebase. I tried to avoid that, but it seems git merge isn’t as smart as patch when it comes to line-offsets.

 0$ git show ea39d8bc9e1b7c23486abc5b28a20d4660fe93dd | patch -p1 --dry-run 
 1checking file .python-version
 2checking file .travis.yml
 3Hunk [#2](/bitcoin-bitcoin/2/) succeeded at 90 with fuzz 1 (offset -20 lines).
 4checking file ci/test/00_setup_env_native_nowallet.sh
 5checking file configure.ac
 6checking file doc/dependencies.md
 7
 8$ git merge ea39d8bc9e1b7c23486abc5b28a20d4660fe93dd
 9Auto-merging doc/dependencies.md
10Auto-merging configure.ac
11Auto-merging .travis.yml
12CONFLICT (content): Merge conflict in .travis.yml
13Automatic merge failed; fix conflicts and then commit the result.

ajtowns commented at 9:21 am on November 18, 2020:

Done

MarcoFalke added the label Needs rebase on Nov 4, 2020

Bump minimum python version to 3.6 8ae9d314e9

[tests] Recommend f-strings for formatting, update feature_block to use them 97c738ff1b

ajtowns force-pushed on Nov 9, 2020

MarcoFalke commented at 8:20 am on November 9, 2020: member

re-ACK 97c738ff1b

for 22.0 only change is rebase

DrahtBot removed the label Needs rebase on Nov 9, 2020

MarcoFalke merged this on Nov 18, 2020

MarcoFalke closed this on Nov 18, 2020

sidhujag referenced this in commit 11a4e5aa0c on Nov 18, 2020

barton2526 referenced this in commit f4c09518fb on Jul 12, 2021

luke-jr referenced this in commit 1cd9a93a36 on Dec 14, 2021

DrahtBot locked this on Feb 15, 2022

Bump minimum python version to 3.6 #19504

Conflicts