def no_prereq_install():
 vals = {'0': False, '1': True, 'true': True, 'false': False}
 val = os.environ.get('NO_PREREQ_INSTALL', 'False').lower()
 try:
  return vals[val]
 except KeyError:
  return False

def no_prereq_install ( ) : vals = { '0' : False , '1' : True , 'true' : True , 'false' : False } val = os . environ . get ( 'NO_PREREQ_INSTALL' , 'False' ) . lower ( ) try : return vals [ val ] except KeyError : return False
determine if no_prereq_install should be truthy or falsy .