dataframe string find count
In [21]: df = pd.DataFrame(['hello', 'world', 'hehe'], columns=['words'])
In [22]: df.words.str.count("he|wo")
Out[22]:
0 1
1 1
2 2
Name: words, dtype: int64
In [23]: df.words.str.count("he|wo").sum()
Out[23]: 4