Format a number with commas to separate thousands in pandas

Given a pandas dataframe, we have to format a number with commas to separate thousands.
Submitted by Pranit Sharma, on September 14, 2022

Pandas is a special tool that allows us to perform complex manipulations of data effectively and efficiently. Inside pandas, we mostly deal with a dataset in the form of DataFrame. DataFrames are 2-dimensional data structures in pandas. DataFrames consist of rows, columns, and data.

Problem statement

Suppose, we have a large DataFrame with a column named X. This column has a field of large numbers (in thousands or lakhs). We need to format these numbers by putting commas in between the digits for proper data analysis.

Format a number with commas to separate thousands

To format a number with commas to separate thousands, you can use pd.options.display method which contains a feature called float_format which will allow us to format these numbers in such a way that they can be separated with commas.

Let us understand with the help of an example,

Python program to format a number with commas to separate thousands in pandas

# Importing pandas package
import pandas as pd

# Creating a dictionary
d = {
     'X':[3128793,
          25728342423,
          24292742,
          345794,
          3968432,
          42075045]
     }

# Creating a DataFrame
df = pd.DataFrame(d)

# Display original DataFrame
print("Original DataFrame:\n",df,"\n")

# Formatting DataFrame
df['X'] = df.apply(lambda x: "{:,}".format(x['X']), axis=1)

# Display modified DataFrame
print("Modified DataFrame:\n",df)