Python Pandas - Return a new Index of the values set with the mask

To return a new Index of the values set with the mask, use the index.putmask() method in Pandas. At first, import the required libraries −

import pandas as pd

Creating Pandas index −

index = pd.Index([5, 65, 10, 17, 75, 40])

Display the Pandas index −

print("Pandas Index...\n",index)

Mask and place index values less than 3 with a value 111 −

print("\nMask...\n",index.putmask(index < 30, 111))

Example

Following is the code −

import pandas as pd

# Creating Pandas index
index = pd.Index([5, 65, 10, 17, 75, 40])

# Display the Pandas index
print("Pandas Index...\n",index)

# Return the number of elements in the Index
print("\nNumber of elements in the index...\n",index.size)

# Return the dtype of the data
print("\nThe dtype object...\n",index.dtype)

# mask and place index values less than 3 with a value 111
print("\nMask...\n",index.putmask(index < 30, 111))

Output

This will produce the following output −

Pandas Index...
Int64Index([5, 65, 10, 17, 75, 40], dtype='int64')

Number of elements in the index...
6

The dtype object...
int64

Mask...
Int64Index([111, 65, 111, 111, 75, 40], dtype='int64')