How to Format Numbers with Commas for Thousands in Pandas

John D K -

To display large numbers in a more readable format we can insert commas as thousands separators in Pandas. This is especially useful when preparing data for presentation or reports.

Below is a quick solution to format numbers with commas using Pandas:

(1) Display Only

df.style.format('{:,}')

or

df.head().style.format("{:,.0f}")

(2) Format parameter for thousands char

df.style.format(thousands=",")

(3) Format multiple columns

col_format = {"sales": "{:,.0f}", "col2": "{:,.0f}"}
df.head().style.format(col_format)

(4) pandas format comma thousands

df['sales'].apply(lambda x: f"{x:,}")

Data

Suppose we have the following DataFrame:

import pandas as pd

df = pd.DataFrame({
    'sales': [1000, 15000, 2500000]
})

df

data:

sales
0 1000
1 15000
2 2500000

Display Commas Without Changing Values

If you only need the formatted output for display purposes:

df.style.format("{:,.0f}")

result:

  sales
0 1,000
1 15,000
2 2,500,000

Multiple Columns with Custom Format

To apply this to multiple numeric columns:

col_format = {"sales": "{:,.0f}", "col2": "{:,.0f}"}
df.head().style.format(col_format)

result:

  sales
0 1,000
1 15,000
2 2,500,000

Format Column with Commas - New Column

Use .apply with Python’s built-in format function to create a new column or update existing one:

import pandas as pd

df = pd.DataFrame({
    'sales': [1000, 15000, 2500000]
})

df['sales_nice'] = df['sales'].apply(lambda x: f"{x:,}")

Output:

sales sales_nice
0 1000 1,000
1 15000 15,000
2 2500000 2,500,000

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