How to get the first column of a Pandas Dataframe?

In this tutorial, we will know how to get the first column of a Pandas Dataframe. Later, we will understand the same with the help of a few examples.

How to get the first column of a Dataframe using Pandas?

We can get the first column of a Dataframe in the following ways:

• by using the column index
• by using column name/label

1. Fetching the first column by index :

In case we are not aware of the first column name then we can always access the first column by the index, using the iloc property.

Syntax: dataFrameName.iloc[:,0]

Note: Columns in a pandas dataframe are indexed starting from 0.

2. Fetching the first column by its name or label :

In order to access the first column by the column name or label, we can use the loc property which allows you to access rows and columns of a dataframe by their labels

Syntax: dataFrameName.loc[:,”firstColumnName”]

Examples:

We will now look at a few examples for a better understanding.

But before that, we will create a pandas dataframe that we will be using throughout this tutorial using the following command:

import pandas as pd

# employee data
data = {
    "Name": ["Jim", "Dwight", "Angela", "Tobi"],
    "Age": [26, 28, 27, 32],
    "Department": ["Sales", "Sales", "Accounting", "HR"]
}

# create pandas dataframe
df = pd.DataFrame(data)
# displays dataframe
df

Output:

Example 1: Access the first column using the column index

Let’s access the first column of the dataframe created above using its column index (column position). Columns are indexed starting from 0, so, the index of the first column is 0.

# get the first column of the dataframe
df.iloc[:, 0]

Output:

0       Jim
1    Dwight
2    Angela
3      Tobi
Name: Name, dtype: object

Example 2: Access the first column using the column name

Alternatively, you can access any column using its name. Now if you know the name of the first column, you can directly access it using the loc property.

# get the column using its name
df.loc[:, "Name"]

Output:

0       Jim
1    Dwight
2    Angela
3      Tobi
Name: Name, dtype: object

You can also directly use the column name using the square bracket notation of the dataframe to access it.

# get the column using its name
df["Name"]

Output:

0       Jim
1    Dwight
2    Angela
3      Tobi
Name: Name, dtype: object

We get the same result as above.

Summary:

In this tutorial, we looked at how to access the first column in a Pandas dataframe. The following are the key takeaways –

• Use the iloc property to access the first column using its index, which is 0.
• Use the loc property to access the first column using its name (or label). Alternatively, you can directly access the column by its name using the [] notation.

You might also be interested in –

• Check if a Column Exists in a Pandas DataFrame
• Check if Pandas DataFrame column has object dtype
• Most frequent value in a Pandas Column
• Split Pandas column of lists into multiple columns
• Pandas – Set Column as Index (With Examples)
• Pandas – Check if a column is all one value