value_counts pandas

col-name.value_count()

df.value_counts(normalize=True) 

df.stack().value_counts()

idx.value_counts()

from collections import Counter
values=np.ones(10)
Counter(values)

>>> index = pd.Index([3, 1, 2, 3, 4, np.nan])
>>> index.value_counts()
3.0    2
4.0    1
2.0    1
1.0    1
dtype: int64