c - How can we shift ob_item pointer in Python tuple if it is static array? -

i reading python 2.7 source code , got stuck following piece of code, in tupleobject.h:

pyobject *ob_item[1]; 

and in tupleobject.c (pytuple_setitem):

p = ((pytupleobject *)op)->ob_item + i; 

how can shift pointer i if ob_item array of 1 pyobject?

it's how arrays , pointers can used interchangeable. it's equivalent to

p = &((pytupleobject *)op)->ob_item[i]; 

is array name pointer? goes little more detail.