String accessor (.str) methods in Data Analysis Python - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the .str accessor in pandas?

The .str accessor allows you to apply string methods to each element in a pandas Series that contains text data, making it easy to manipulate text in columns.

beginner

How do you convert all text in a pandas Series to lowercase using .str methods?

Use series.str.lower() to convert all characters in each string of the Series to lowercase.

beginner

What does series.str.contains('abc') do?

It checks each string in the Series to see if it contains the substring 'abc' and returns a Series of True or False values.

beginner

How can you extract the first 3 characters from each string in a pandas Series?

Use series.str[:3] to slice the first three characters from each string in the Series.

beginner

What will series.str.replace('a', 'x') do?

It replaces every occurrence of the letter 'a' with 'x' in each string of the Series.

Which pandas method would you use to check if strings in a Series start with 'Hello'?

A series.str.contains('Hello')

B series.str.match('Hello')

C series.str.find('Hello')

D series.str.startswith('Hello')

The startswith() method checks if each string starts exactly with the given substring.

What does series.str.len() return?

A The length of each string in the Series

B The total number of strings in the Series

C The number of unique strings

D The number of missing values

str.len() returns a Series with the length of each string element.

How do you remove whitespace from the start and end of strings in a Series?

A series.str.remove()

B series.str.trim()

C series.str.strip()

D series.str.clean()

str.strip() removes whitespace from both ends of each string.

Which method splits strings in a Series by a delimiter?

A series.str.split(',')

B series.str.divide(',')

C series.str.cut(',')

D series.str.partition(',')

str.split() splits each string into a list using the delimiter.

What type of object is returned by series.str.extract(r'(\d+)')?

A A Series of booleans

B A DataFrame with extracted groups

C A list of strings

D An integer count

str.extract() returns a DataFrame with the matched groups from the regex.

Explain how the .str accessor helps when working with text data in pandas Series.

Think about how you would handle text in many rows at once.

Describe three common string operations you can perform using pandas .str methods.

Consider operations useful for cleaning or analyzing text.