python dict: get vs setdefault

Question

The following two expressions seem equivalent to me. Which one is preferable?

data = [(\'a\', 1), (\'b\', 1), (\'b\', 2)]

d1 = {}
d2 = {}

for key, val in d         


        

Answer 1

In [1]: person_dict = {}

In [2]: person_dict['liqi'] = 'LiQi'

In [3]: person_dict.setdefault('liqi', 'Liqi')
Out[3]: 'LiQi'

In [4]: person_dict.setdefault('Kim', 'kim')
Out[4]: 'kim'

In [5]: person_dict
Out[5]: {'Kim': 'kim', 'liqi': 'LiQi'}

In [8]: person_dict.get('Dim', '')
Out[8]: ''

In [5]: person_dict
Out[5]: {'Kim': 'kim', 'liqi': 'LiQi'}