ENH: port time.pxd from cython

[jbrockmendel]

Until cython3 is out, we port it here. This will allow a cython implementation of dateutil's tzlocal, which will [yak-shaving] for non-nano dt64/td64.

[mroeschke]

Actually, looks like this doesn't build on windows?

building 'pandas._libs.tslibs.ctime' extension
ctime.c
pandas\_libs/tslibs/ctime.c(2383): error C2039: 'tm_zone': is not a member of 'tm'
C:\Program Files (x86)\Windows Kits\10\include\10.0.22000.0\ucrt\corecrt_wtime.h(26): note: see declaration of 'tm'
pandas\_libs/tslibs/ctime.c(2383): error C2198: 'PyBytes_FromString': too few arguments for call
pandas\_libs/tslibs/ctime.c(2386): error C2039: 'tm_gmtoff': is not a member of 'tm'
C:\Program Files (x86)\Windows Kits\10\include\10.0.22000.0\ucrt\corecrt_wtime.h(26): note: see declaration of 'tm'
pandas\_libs/tslibs/ctime.c(2386): error C2198: '__Pyx_PyInt_From_long': too few arguments for call
error: command 'C:\\Program Files (x86)\\Microsoft Visual Studio\\2019\\Enterprise\\VC\\Tools\\MSVC\\14.29.30133\\bin\\HostX86\\x64\\cl.exe' failed with exit code 2

[jbrockmendel]

Actually, looks like this doesn't build on windows?

Well that doesn't look good. @scoder area the analogous tests not run on any windows builds in the cython CI?

[scoder]

are the analogous tests not run on any windows builds in the cython CI?

libc/time.pxd is different in 0.29.x. It still contains two struct fields that were commented out in 3.0 because they are GNU specific. Removing them from 0.29.x would be a backwards incompatible change, though.

https://github.com/cython/cython/blob/f0ccd6851e80654585fa6acb7a0626bf615857fe/Cython/Includes/libc/time.pxd
cython/cython@1a6bba9

Note that the field declarations shouldn't hurt as long as you're not trying to (auto-)convert the struct into a Python dict. So you can probably get by with adapting the tests Python exposed functions.

[mroeschke]

pandas/tests/tslibs/test_ctime.py:10: error: Module "pandas._libs.tslibs" has no attribute "ctime" [attr-defined]

[mroeschke]

Thanks @jbrockmendel