Checking data types in Data Analysis Python - Cheat Sheet & Quick Revision

Recall & Review

beginner

What function in pandas is used to check the data type of each column in a DataFrame?

The DataFrame.dtypes attribute shows the data type of each column in a pandas DataFrame.

beginner

How can you check the data type of a single variable in Python?

Use the built-in type() function to find the data type of any Python variable.

beginner

What does the data type object usually mean in a pandas DataFrame?

In pandas, object usually means the column contains text (strings) or mixed types.

beginner

Why is it important to check data types before analysis?

Checking data types helps ensure correct calculations and prevents errors, like trying to add text to numbers.

intermediate

How can you convert a column to a different data type in pandas?

Use DataFrame['column'].astype(new_type) to change a column's data type, for example to int or float.

Which pandas attribute shows the data types of all columns in a DataFrame?

A info

B dtype

C dtypes

D type

The dtypes attribute lists the data type of each column.

What Python function tells you the type of a variable?

A typeof()

B type()

C checktype()

D gettype()

The built-in function type() returns the data type of a variable.

If a pandas column shows data type object, what does it usually contain?

A Text or mixed types

B Numbers only

C Dates only

D Boolean values

object type usually means text strings or mixed data.

Why should you check data types before doing calculations?

A To make data look colorful

B To speed up the computer

C To delete unwanted data

D To avoid errors and wrong results

Correct data types prevent errors and ensure calculations work properly.

How do you change a pandas column to integer type?

A astype('int')

B convert('int')

C change_type('int')

D to_int()

Use astype('int') to convert a column to integer type.

Explain how to check the data types of columns in a pandas DataFrame and why it matters.

Think about how pandas stores text and numbers differently.

Describe how to find the data type of a single variable in Python and how to change a pandas column's data type.

One is a Python function, the other is a pandas method.