BUG: Bug in comparing duplicate frames (GH4421) related
BUG: Bug in describe on duplicate frames
Merge pull request #5194 from jreback/dup_eq

BUG: Bug in comparing duplicate frames (GH4421) related
BUG: Bug in to_datetime with a format and coerce=True not raising (GH5195)
Merge pull request #5197 from jreback/to_datetime

BUG: Bug in to_datetime with a format and coerce=True not raising (GH5195)
inlined some functions and avoid repeated conversion factor calculation when using period_asfreq_arr in period.c