Arithmetic operations on columns in Pandas - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does adding two columns in a pandas DataFrame do?

It adds the values in each row from the two columns and creates a new column with these sums.

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How do you subtract one column from another in pandas?

You use the minus (-) operator between the two columns, like df['col1'] - df['col2'].

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What happens if you multiply a column by a number in pandas?

Each value in the column is multiplied by that number, scaling the entire column.

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How can you create a new column that is the result of dividing one column by another?

Use the division operator (/) between the two columns, like df['col1'] / df['col2'].

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Why is it useful to perform arithmetic operations on DataFrame columns?

It helps to create new insights or features by combining or transforming existing data easily.

What does df['A'] + df['B'] do in pandas?

A Creates a list of columns A and B

B Concatenates columns A and B as strings

C Deletes columns A and B

D Adds values of columns A and B row-wise

Adding two columns sums their values for each row.

How do you multiply all values in column 'X' by 10?

A df['X'] - 10

B df['X'] + 10

C df['X'] * 10

D df['X'] / 10

Multiplying a column by 10 scales each value by 10.

Which operator divides one column by another in pandas?

A +

B /

C *

D -

The division operator (/) divides values of one column by another.

What will df['C'] = df['A'] - df['B'] do?

A Create column C with row-wise difference of A and B

B Add columns A and B into C

C Multiply columns A and B into C

D Delete columns A and B

Subtracting columns creates a new column with their difference.

Why perform arithmetic on DataFrame columns?

A To create new data insights

B To delete data

C To rename columns

D To sort data

Arithmetic operations help generate new useful data from existing columns.

Explain how to add two columns in a pandas DataFrame and why you might do this.

Think about combining data from two columns to get a total.

Describe how to multiply a DataFrame column by a number and what effect this has on the data.

Consider how changing each value by a fixed number changes the data.