How to Return a Boolean Array True Where the String Array Ends with Suffix Using NumPy?

In this article, we will discuss how to return a boolean array that is True where the string element in the array ends with a suffix using NumPy in Python.

Example: Check the array ends with Com 
Input: [email protected]
Output: True
Input: [email protected]
Output: False

In Python, numpy.char module provides a set of vectorized string operations for arrays of type numpy.str_. We can use Numpy.char.endswith method to return a Boolean array which is True where the string element in array ends with suffix.

Syntax: char.endswith(a, suffix, start=0, end=None)

Parameters

• a: array_like of str or unicode
• suffix: str
• start, end: int, optional
• With optional start, test beginning at that position. With optional end, stop comparing at that position.

Returns

• out: ndarray
• Outputs an array of bools.

Example 1:

We have an array of Email addresses, we need to check which of them are valid emails by checking the suffix ".com". If a string ends with ".com" it should return True otherwise False.

# import required modules
import numpy as np

# initialising the array to be validated
address_list = np.array(["[email protected]",
                         "[email protected]",
                         "[email protected]"])

# Calling the endswith method
validated_array = np.char.endswith(address_list,
                                   suffix = ".com")

print(validated_array)

Output:

[ True False  True]

Example 2:

In the previous example, we have validated the email address with the suffix ".com", now we will validate the domain of the email address. This time we are interested in the domain "abc" only, not ".com"

The address with domain abc should return True otherwise False. Assume that, there will be exactly 4 characters after the domain(ex: ".com")

# import required modules
import numpy as np

# initialising the array to be validated
address_list = np.array(["[email protected]",
                         "[email protected]",
                         "[email protected]"])

# Calling the endswith method
# start = 0 : starts from the beginning of
# a stringend = -4 : Ends at 4 places before
# the string ending
validated_array = np.char.endswith(address_list,
                                   suffix ="abc",
                                   start=0, end=-4)

print(validated_array)

Output:

[ True  True False]