Add Python 2.7 sunset message to Calculator constructor

[martinholmer]

This pull request notifies Tax-Calculator users that beginning in 2019 Python 2.7 will not be supported: the source code will be Python 3.6 and conda taxcalc packages will be available only for Python 3.6.

The user documentation already instructs users to install Python 3.6 (and not 2.7) and the contributor guide already says the same thing. And the developers of projects that are known to use Tax-Calculator have been directly notified of this future change. So, we have given a comprehensive early warning of this major change.

[codecov-io]

Codecov Report

Merging #1923 into master will not change coverage.
The diff coverage is 100%.

@@          Coverage Diff           @@
##           master   #1923   +/-   ##
======================================
  Coverage     100%    100%           
======================================
  Files          38      38           
  Lines        3588    3594    +6     
======================================
+ Hits         3588    3594    +6

Impacted Files	Coverage Δ
taxcalc/calculate.py	100% <100%> (ø)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update d44a7d5...9aafe89. Read the comment docs.

[MattHJensen]

LGTM. Thanks @martinholmer.

[MaxGhenis]

Do you know if it's possible to warn upon loading the package? I couldn't find a way with a cursory search, but this would be nice for users who create many Calculator objects in the same session (like me...) and get warned multiple times.

[martinholmer]

@MaxGhenis asked:

Do you know if it's possible to warn upon loading the package? I couldn't find a way with a cursory search, but this would be nice for users who create many Calculator objects in the same session (like me...) and get warned multiple times.

No I don't know how to do that. But if you are getting tired of reading the warning and don't want to get rid of it by upgrading to Python 3.6, then simply set verbose=False in the Calculator class constructor. That should suppress the warning.

[MaxGhenis]

Thanks!

…

On Fri, Mar 16, 2018 at 4:34 PM Martin Holmer ***@***.***> wrote: @MaxGhenis <https://github.com/maxghenis> asked: Do you know if it's possible to warn upon loading the package? I couldn't find a way with a cursory search, but this would be nice for users who create many Calculator objects in the same session (like me...) and get warned multiple times. No I don't know how to do that. But if you are getting tired of reading the warning and don't want to get rid of it by upgrading to Python 3.6, then simply set verbose=False in the Calculator class constructor. That should suppress the warning. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#1923 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AFy2z8SpUNPwxhgKakRtg2_rPh5-ElKEks5tfEwPgaJpZM4Sq-_h> .