DataFrame – Attributes and Methods

The Pandas DataFrame is a Two-dimensional, tabular data, that uses the DataFrame() method to create a DataFrame. It also uses different built-in attributes and methods for basic functionalities. In this lesson, let us see such attributes and methods in Python Pandas for DataFrame:

  • dtypes: Return the dtypes in the DataFrame
  • ndim: Return the number of dimensions of the DataFrame
  • size: Return the number of elements in the DataFrame.
  • shape: Return the dimensionality of the DataFrame in the form of a tuple.
  • index: Return the index of the DataFrame
  • T: Transpose the rows and columns
  • head(): Return the first n rows.
  • tail(): Return the last n rows.

Before moving further, we’ve prepared a video tutorial to learn DataFrame Attributes and Methods:

Let us understand the attributes and methods:

dtypes

The pandas.DataFrame.dtypes is used to return the dtypes in the DataFrame.

Let us now see an example to implement the dtypes attribute in Python Pandas:

import pandas as pd

# Dataset
data = {
    'Student': ["Amit", "John", "Jacob", "David", "Steve"],
    'Rank': [1, 4, 3, 5, 2],
    'Marks': [95, 70, 80, 60, 90]
}

# Create a DataFrame using the DataFrame() method with index
res = pd.DataFrame(data, index=['RowA', 'RowB', 'RowC', 'RowD', 'RowE'], )

# Display the Records
print("Student Records\n\n", res)

# Datatypes in the DataFrame
print("\nDatatypes:\n", res.dtypes)

Output

Student Records

      Student  Rank  Marks
RowA    Amit     1     95
RowB    John     4     70
RowC   Jacob     3     80
RowD   David     5     60
RowE   Steve     2     90

Datatypes:
Student    object
Rank        int64
Marks       int64
dtype: object

ndim

The pandas.DataFrame.ndim is used to return the number of dimensions of the DataFrame.

Let us now see an example to implement the ndim attribute in Python Pandas:

import pandas as pd

# Dataset
data = {
    'Student': ["Amit", "John", "Jacob", "David", "Steve"],
    'Rank': [1, 4, 3, 5, 2],
    'Marks': [95, 70, 80, 60, 90]
}

# Create a DataFrame using the DataFrame() method with index
res = pd.DataFrame(data, index=['RowA', 'RowB', 'RowC', 'RowD', 'RowE'], )

# Display the Records
print("Student Records\n\n", res)

# Number of Dimensions in the DataFrame
print("\nNumber of Dimensions:\n", res.ndim)

Output

Student Records

      Student  Rank  Marks
RowA    Amit     1     95
RowB    John     4     70
RowC   Jacob     3     80
RowD   David     5     60
RowE   Steve     2     90

Number of Dimensions:
 2

size

The pandas.DataFrame.size is used to return the number of elements in the DataFrame.

Let us now see an example to implement the size attribute in Python Pandas:

import pandas as pd

# Dataset
data = {
    'Student': ["Amit", "John", "Jacob", "David", "Steve"],
    'Rank': [1, 4, 3, 5, 2],
    'Marks': [95, 70, 80, 60, 90]
}

# Create a DataFrame using the DataFrame() method with index
res = pd.DataFrame(data, index=['RowA', 'RowB', 'RowC', 'RowD', 'RowE'], )

# Display the Records
print("Student Records\n\n", res)

# Number of elements in the DataFrame
print("\nNumber of Elements:\n", res.size)

Output

Student Records

      Student  Rank  Marks
RowA    Amit     1     95
RowB    John     4     70
RowC   Jacob     3     80
RowD   David     5     60
RowE   Steve     2     90

Number of Elements:
 15

shape

The pandas.DataFrame.shape is used to return the dimensionality of the DataFrame in the form of a tuple.

Let us now see an example to implement the shape attribute in Python Pandas:

import pandas as pd

# Dataset
data = {
    'Student': ["Amit", "John", "Jacob", "David", "Steve"],
    'Rank': [1, 4, 3, 5, 2],
    'Marks': [95, 70, 80, 60, 90]
}

# Create a DataFrame using the DataFrame() method with index
res = pd.DataFrame(data, index=['RowA', 'RowB', 'RowC', 'RowD', 'RowE'], )

# Display the Records
print("Student Records\n\n", res)

# Return the dimensionality of the DataFrame
# Result in a Tuple form
print("\nDimensionality:\n", res.shape)

Output

Student Records

      Student  Rank  Marks
RowA    Amit     1     95
RowB    John     4     70
RowC   Jacob     3     80
RowD   David     5     60
RowE   Steve     2     90

Dimensionality:
 (5, 3)

index

The pandas.DataFrame.index is used to return the index of the DataFrame.

Let us now see an example to implement the index attribute in Python Pandas:

import pandas as pd

# Dataset
data = {
    'Student': ["Amit", "John", "Jacob", "David", "Steve"],
    'Rank': [1, 4, 3, 5, 2],
    'Marks': [95, 70, 80, 60, 90]
}

# Create a DataFrame using the DataFrame() method with index
res = pd.DataFrame(data, index=['RowA', 'RowB', 'RowC', 'RowD', 'RowE'], )

# Display the Records
print("Student Records\n\n", res)

# Return the index of the DataFrame
print("\nDataFrame Index:\n", res.index)

Output

Student Records

      Student  Rank  Marks
RowA    Amit     1     95
RowB    John     4     70
RowC   Jacob     3     80
RowD   David     5     60
RowE   Steve     2     90

DataFrame Index:
 Index(['RowA', 'RowB', 'RowC', 'RowD', 'RowE'], dtype='object')

T

The pandas.DataFrame.T is used to Transpose the rows and columns.

Let us now see an example to implement the T attribute in Python Pandas:

import pandas as pd

# Dataset
data = {
    'Student': ["Amit", "John", "Jacob", "David", "Steve"],
    'Rank': [1, 4, 3, 5, 2],
    'Marks': [95, 70, 80, 60, 90]
}

# Create a DataFrame using the DataFrame() method with index
res = pd.DataFrame(data, index=['RowA', 'RowB', 'RowC', 'RowD', 'RowE'], )

# Display the Records
print("Student Records\n\n", res)

# Return the Transpose
print("\nTranspose:\n", res.T)

Output

Student Records

      Student  Rank  Marks
RowA    Amit     1     95
RowB    John     4     70
RowC   Jacob     3     80
RowD   David     5     60
RowE   Steve     2     90

Transpose:
          RowA  RowB   RowC   RowD   RowE
Student  Amit  John  Jacob  David  Steve
Rank        1     4      3      5      2
Marks      95    70     80     60     90

head()

The pandas.DataFrame.head() is used to return the first n rows.

Let us now see an example to implement the head() method in Python Pandas:

import pandas as pd

# Dataset
data = {
    'Student': ["Amit", "John", "Jacob", "David", "Nathan", "Steve"],
    'Rank': [1, 4, 3, 5, 6, 2],
    'Marks': [95, 70, 80, 60, 55, 90]
}

# Create a DataFrame using the DataFrame() method with index
res = pd.DataFrame(data, index=['RowA', 'RowB', 'RowC', 'RowD', 'RowE', 'RowF'], )

# Display the Records
print("Student Records\n\n", res)

# Return the first n rows
# Default value of n is 5
print("\nFirst 5 rows:\n", res.head())

Output

Student Records

      Student  Rank  Marks
RowA    Amit     1     95
RowB    John     4     70
RowC   Jacob     3     80
RowD   David     5     60
RowE  Nathan     6     55
RowF   Steve     2     90

First 5 rows:
      Student  Rank  Marks
RowA    Amit     1     95
RowB    John     4     70
RowC   Jacob     3     80
RowD   David     5     60
RowE  Nathan     6     55

tail()

The pandas.DataFrame.tail() is used to return the last n rows.

Let us now see an example to implement the tail() method in Python Pandas:

import pandas as pd

# Dataset
data = {
    'Student': ["Amit", "John", "Jacob", "David", "Nathan", "Steve"],
    'Rank': [1, 4, 3, 5, 6, 2],
    'Marks': [95, 70, 80, 60, 55, 90]
}

# Create a DataFrame using the DataFrame() method with index
res = pd.DataFrame(data, index=['RowA', 'RowB', 'RowC', 'RowD', 'RowE', 'RowF'], )

# Display the Records
print("Student Records\n\n", res)

# Return the last n rows
# Default value of n is 5
print("\nLast 5 rows:\n", res.tail())

Output

Student Records

      Student  Rank  Marks
RowA    Amit     1     95
RowB    John     4     70
RowC   Jacob     3     80
RowD   David     5     60
RowE  Nathan     6     55
RowF   Steve     2     90

Last 5 rows:
      Student  Rank  Marks
RowB    John     4     70
RowC   Jacob     3     80
RowD   David     5     60
RowE  Nathan     6     55
RowF   Steve     2     90

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Read More:

Pandas Series - Attributes and Methods
Sorting in Pandas
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