How to Use Excel's MOD Function in Pandas

Excel's MOD function returns the remainder after a number is divided. For example, =MOD(10, 3) returns 1, since 10 divided by 3 leaves a remainder of 1.

This page explains how you on can replicate Excel's MOD function in Python using pandas.

Implementing the Modulus function in Pandas#

To perform modulus operations in Python using pandas, you can use the `%` operator. This works similarly to Excel's MOD function.

Basic Modulus Operation#

The basic modulus operation in pandas is straightforward. For example, in Excel if you wanted to check if a number is even, you could use =MOD(A2, 2).

In pandas, you can use the following code to return 0 if the number is even, and 1 if it's odd.

df['Result'] = df['Column1'] % 2

Copy!

Applying Modulus Across Rows#

To apply the modulus operation across rows, you can use a second column as the divisor instead of hard-coding a number.

This would be equivalent to using =MOD(A2, B2) in Excel.

df['Result'] = df['Column1'] % df['Column2']

Copy!

ISODD function#

Excel has a built-in ISODD function that returns TRUE if a number is odd, and FALSE if it's even. You can replicate this in pandas using the following code:

df['Result'] = df['Column1'] % 2 == 1

Copy!

ISEVEN function#

Excel has a built-in ISEVEN function that returns TRUE if a number is even, and FALSE if it's odd. You can replicate this in pandas using the following code:

df['Result'] = df['Column1'] % 2 == 0

Copy!

Common mistakes when using MOD in Python#

When implementing the MOD function in pandas, it's important to be aware of common pitfalls. Here are some to avoid:

Incorrect Data Types#

Attempting modulus on non-numeric columns will lead to errors. Ensure all columns involved in the operation are numeric. For example, if 'Column1' or 'Column2' contains strings, the code will return an error.

To fix it, convert the columns to numeric first. This will convert any non-numeric values to NaN, which can be handled using fillna(1) so that the result is 0 for any NaN divisors.

# Convert to numeric and fill missing values with 1
df['Column1'] = pd.to_numeric(df['Column1'], errors='coerce').fillna(1)
df['Column2'] = pd.to_numeric(df['Column2'], errors='coerce').fillna(1)

# Perform modulus operation
df['Result'] = df['Column1'] % df['Column2']

Copy!

Understanding the Modulus Formula in Excel#

In Excel, the MOD function takes two arguments: the number to be divided and the divisor.

=MOD(number, divisor)

MOD Excel Syntax

Examples