CLN: no return on init
CLN: no return on init

Author: Maximilian Roos <maximilian@sixtycapital.com>

Closes #13197 from MaximilianR/init-return and squashes the following commits:

ee5072a [Maximilian Roos] formatting

jreback/pandas,jmmease/pandas,Winand/pandas,MJuddBooth/pandas,louispotok/pandas,jreback/pandas,toobaz/pandas,jmmease/pandas,kdebrab/pandas,dsm054/pandas,pandas-dev/pandas,rs2/pandas,jorisvandenbossche/pandas,pratapvardhan/pandas,linebp/pandas,DGrady/pandas,zfrenchee/pandas,GuessWhoSamFoo/pandas,harisbal/pandas,TomAugspurger/pandas,harisbal/pandas,cbertinato/pandas,linebp/pandas,rs2/pandas,linebp/pandas,gfyoung/pandas,nmartensen/pandas,MJuddBooth/pandas,gfyoung/pandas,pandas-dev/pandas,GuessWhoSamFoo/pandas,cython-testbed/pandas,winklerand/pandas,MJuddBooth/pandas,GuessWhoSamFoo/pandas,cbertinato/pandas,datapythonista/pandas,DGrady/pandas,jmmease/pandas,nmartensen/pandas,dsm054/pandas,nmartensen/pandas,cython-testbed/pandas,winklerand/pandas,winklerand/pandas,gfyoung/pandas,zfrenchee/pandas,harisbal/pandas,pratapvardhan/pandas,MJuddBooth/pandas,jmmease/pandas,winklerand/pandas,zfrenchee/pandas,kdebrab/pandas,jreback/pandas,jreback/pandas,amolkahat/pandas,kdebrab/pandas,cbertinato/pandas,datapythonista/pandas,toobaz/pandas,dsm054/pandas,linebp/pandas,harisbal/pandas,dsm054/pandas,jorisvandenbossche/pandas,DGrady/pandas,pandas-dev/pandas,dsm054/pandas,pratapvardhan/pandas,winklerand/pandas,cython-testbed/pandas,louispotok/pandas,pratapvardhan/pandas,toobaz/pandas,jorisvandenbossche/pandas,amolkahat/pandas,cbertinato/pandas,louispotok/pandas,rs2/pandas,Winand/pandas,rs2/pandas,DGrady/pandas,louispotok/pandas,zfrenchee/pandas,Winand/pandas,amolkahat/pandas,harisbal/pandas,Winand/pandas,jreback/pandas,datapythonista/pandas,louispotok/pandas,kdebrab/pandas,linebp/pandas,cython-testbed/pandas,nmartensen/pandas,Winand/pandas,pandas-dev/pandas,kdebrab/pandas,jmmease/pandas,cbertinato/pandas,cython-testbed/pandas,jmmease/pandas,DGrady/pandas,toobaz/pandas,winklerand/pandas,toobaz/pandas,amolkahat/pandas,GuessWhoSamFoo/pandas,nmartensen/pandas,gfyoung/pandas,nmartensen/pandas,zfrenchee/pandas,jorisvandenbossche/pandas,linebp/pandas,MJuddBooth/pandas,TomAugspurger/pandas,amolkahat/pandas,TomAugspurger/pandas,GuessWhoSamFoo/pandas,pratapvardhan/pandas,Winand/pandas,gfyoung/pandas,TomAugspurger/pandas,DGrady/pandas,datapythonista/pandas