pandas get count of each value in column code example

Example 1: pandas count rows with value

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

Example 2: pandas get count of column

df['column_name'].value_counts()

Example 3: pandas count values by column

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

Example 4: pandas count number of rows with value

In [37]:
df = pd.DataFrame({'a':list('abssbab')})
df.groupby('a').count()

Out[37]:

   a
a   
a  2
b  3
s  2

[3 rows x 1 columns]