How to iterate over Pandas Series generated from groupby().size()

Update:

Given a pandas Series:

s = pd.Series([1,2,3,4], index=['a', 'b', 'c', 'd'])

s
#a    1
#b    2
#c    3
#d    4
#dtype: int64

You can directly loop through it, which yield one value from the series in each iteration:

for i in s:
    print(i)
1
2
3
4

If you want to access the index at the same time, you can use either items or iteritems method, which produces a generator that contains both the index and value:

for i, v in s.items():
    print('index: ', i, 'value: ', v)
#index:  a value:  1
#index:  b value:  2
#index:  c value:  3
#index:  d value:  4

for i, v in s.iteritems():
    print('index: ', i, 'value: ', v)
#index:  a value:  1
#index:  b value:  2
#index:  c value:  3
#index:  d value:  4

Old Answer:

You can call iteritems() method on the Series:

for i, row in df.groupby('a').size().iteritems():
    print(i, row)

# 12 4
# 14 2

According to doc:

Series.iteritems()

Lazily iterate over (index, value) tuples

Note: This is not the same data as in the question, just a demo.