pandas count values code example

Example 1: df sort values

>>> df.sort_values(by=['col1'], ascending = False)
    col1 col2 col3
0   A    2    0
1   A    1    1
2   B    9    9
5   C    4    3
4   D    7    2
3   NaN  8    4

Example 2: count values pandas

>>> 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

Example 3: pandas count rows with value

len(df[df['score'] == 1.0])

Example 4: value count in python

col-name.value_count()

Example 5: frequency unique pandas

df.stack().value_counts()

Example 6: pandas count values by column

df = pd.DataFrame({'a':list('abssbab')})
df.groupby('a').count()