index = df.index
number_of_rows = len(index)
>>> df.count(axis='columns')
0 3
1 2
2 3
3 3
4 3
dtype: int64
number_of_rows = len(df)
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]
len(df)