How To Read a CSV file Without a Header in Pandas – Definitive Guide

Some CSV files might not have headers in them.

You can read csv file without a header in pandas using the read_csv() method and header=none parameter.

This tutorial teaches you how to read a CSV file without a header in Pandas.

If you’re in Hurry

Use the following code to read the CSV file without a header and set column names manually.

import pandas as pd

df = pd.read_csv('addresses.csv', header=None, names=['First Name', 'Last Name', 'Address', 'State', 'Zip Code'])

df

If You Want to Understand Details, Read on…

Pandas read_csv() reads the first row as a header by default. If the CSV file does not contain a header, you need to pass the header=None to tell pandas that the first row is also a data row.

Using ReadCSV And Header=None

By default, the pandas read_csv() method considers the first row of the CSV file as the header.

• To read a CSV file without a header in Pandas, you need to pass the header=None parameter.
• This parameter denotes that the first line in the CSV file is also a data row, not a header row.

Code

The following code demonstrates how to use the header=None parameter in the read_csv() method.

import pandas as pd

df = pd.read_csv('addresses.csv', header=None)

df

Dataframe Will Look Like

	0	1	2	3	4	5
0	John	Doe	120 jefferson st.	Riverside	NJ	8075
1	Jack	McGinnis	220 hobo Av.	Phila	PA	9119
2	John “Da Man”	Repici	120 Jefferson St.	Riverside	NJ	8075
3	Stephen	Tyler	7452 Terrace “At the Plaza” road	SomeTown	SD	91234
4	NaN	Blankman	NaN	SomeTown	SD	298
5	Joan “the bone”, Anne	Jet	9th, at Terrace plc	Desert City	CO	123

Read CSV Without Header and Set Column Names

To read a CSV file without a header and set column names, you can use the header=None parameter and pass the column headers using the names parameter.

You can pass the columns as a list to the names parameter. For example, names = [‘Col 1’, ‘Col 2’] and so on.

Code

The following code demonstrates how to set the column names while reading the CSV file.

import pandas as pd

df = pd.read_csv('addresses.csv', header=None, names=['First Name', 'Last Name', 'Address', 'State', 'Zip Code'])

df

Dataframe Will Look Like

	First Name	Last Name	Address	State	Zip Code
John	Doe	120 jefferson st.	Riverside	NJ	8075
Jack	McGinnis	220 hobo Av.	Phila	PA	9119
John “Da Man”	Repici	120 Jefferson St.	Riverside	NJ	8075
Stephen	Tyler	7452 Terrace “At the Plaza” road	SomeTown	SD	91234
NaN	Blankman	NaN	SomeTown	SD	298
Joan “the bone”, Anne	Jet	9th, at Terrace plc	Desert City	CO	123

Read Specific Columns From CSV Without Header

To read specific columns from CSV, use the usecols parameter and pass the index of the columns as a list.

• It reads the columns specified in the list
• Uses the column names passed in the names parameter.

Code

The following code demonstrates how to read the columns with index 1 and 2 from the CSV file without a header.

import pandas as pd

df = pd.read_csv('addresses.csv', header=None, usecols=[1,2], names=['First Name', 'Last Name'])

df

Dataframe Will Look Like

	First Name	Last Name
0	Doe	120 jefferson st.
1	McGinnis	220 hobo Av.
2	Repici	120 Jefferson St.
3	Tyler	7452 Terrace “At the Plaza” road
4	Blankman	NaN
5	Jet	9th, at Terrace plc

Additional Resources

• How To Replace Header With First Row In Pandas Dataframe
• How to Remove the Header Row From Pandas Dataframe
• How to Read a CSV file From a URL in Pandas (With Authentication)
• How To Read Specific Columns From a CSV using Pandas Python
• How to Remove the Index Column in Pandas While Reading from the CSV file