Cython language level 3

[WillAyd]

• closes Cython language_level Warning - switch to Python3? #23927

[jreback]

lgtm. ping on green.

[jbrockmendel]

I think there are places where we do isinstance Unicode checks, may be worth updating

[codecov]

Codecov Report

Merging #24538 into master will decrease coverage by 49.29%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master   #24538      +/-   ##
==========================================
- Coverage   92.32%   43.02%   -49.3%     
==========================================
  Files         166      166              
  Lines       52429    52429              
==========================================
- Hits        48403    22557   -25846     
- Misses       4026    29872   +25846

Flag	Coverage Δ
#multiple	?
#single	43.02% <ø> (ø)	⬆️

Impacted Files	Coverage Δ
pandas/io/formats/latex.py	0% <0%> (-100%)	⬇️
pandas/core/categorical.py	0% <0%> (-100%)	⬇️
pandas/io/sas/sas_constants.py	0% <0%> (-100%)	⬇️
pandas/tseries/plotting.py	0% <0%> (-100%)	⬇️
pandas/tseries/converter.py	0% <0%> (-100%)	⬇️
pandas/io/formats/html.py	0% <0%> (-98.68%)	⬇️
pandas/core/groupby/categorical.py	0% <0%> (-95.46%)	⬇️
pandas/io/sas/sas7bdat.py	0% <0%> (-91.17%)	⬇️
pandas/io/sas/sas_xport.py	0% <0%> (-90.15%)	⬇️
pandas/core/tools/numeric.py	10.44% <0%> (-89.56%)	⬇️
... and 124 more

---

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Δ = absolute <relative> (impact), ø = not affected, ? = missing data
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[codecov]

Codecov Report

Merging #24538 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master   #24538   +/-   ##
=======================================
  Coverage   91.25%   91.25%           
=======================================
  Files         172      172           
  Lines       52977    52977           
=======================================
  Hits        48342    48342           
  Misses       4635     4635

Flag	Coverage Δ
#multiple	89.82% <ø> (ø)	⬆️
#single	41.74% <ø> (ø)	⬆️

---

Continue to review full report at Codecov.

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Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 707c720...b7ccc62. Read the comment docs.

[WillAyd]

I think there are places where we do isinstance Unicode checks, may be worth updating

Yep I do see a few. Going to try and get green as is first then do this on a subsequent pass

[WillAyd]

All failures are for the 2.7 builds; are we still worrying about them at this point?

[jreback]

only if you want to merge this for 0.24

[WillAyd]

I don't think it necessarily adds anything to 0.24 from an end user perspective so fine to wait on my end

[WillAyd]

Just rebasing to minimize diff in future; no rush for action here

[WillAyd]

@jreback I think timing is finally right for merge here.

To @jbrockmendel point above there are still some isinstance unicode checks that could be cleaned up, but I figure that's better left in follow ups to rip out Py2 compat. This as is is minimum to get language level switched over to 3 syntax

[jreback]

thanks @WillAyd