filter-by-regex.md

Filter By Regex

Some people, when confronted with a problem, think "I know, I'll use regular expressions." Now they have two problems. --Jamie Zawinski

Jokes aside, I love regex. Here's how you filter data in a pandas DataFrame using regex. Suppose we have a csv of addresses, with a street column, and we want to find Sesame Street, then we would reference that column, use the str attribute, and use the match() method. The kicker is remembering to use the str attribute before using the match() or contains() methods.

import pandas

df = pandas.read_csv('addresses.csv')
result = df[df['street'].str.match(r'Sesame')]

References

• Series.str.match()
• Series.str.contains()