NumPy: Test digits only, lower case and upper case letters only

Last update on December 21 2024 07:39:50 (UTC/GMT +8 hours)

Write a NumPy program to check whether each element of a given array is composed of digits only, lower case letters only and upper case letters only.

Sample Solution:

Python Code:

# Importing necessary library
import numpy as np

# Creating a NumPy array containing strings
x = np.array(['Python', 'PHP', 'JS', 'Examples', 'html5', '5'], dtype=np.str)

# Displaying the content of the original array
print("\nOriginal Array:")
print(x)

# Checking if each element contains digits only
r1 = np.char.isdigit(x)

# Checking if each element contains lower case letters only
r2 = np.char.islower(x)

# Checking if each element contains upper case letters only
r3 = np.char.isupper(x)

# Displaying results
print("Digits only =", r1)
print("Lower cases only =", r2)
print("Upper cases only =", r3) 

Sample Input:

(['Python', 'PHP', 'JS', 'Examples', 'html5', '5'], dtype=np.str)

Sample Output:

Original Array:
['Python' 'PHP' 'JS' 'Examples' 'html5' '5']
Digits only = [False False False False False  True]
Lower cases only = [False False False False  True False]
Upper cases only = [False  True  True False False False]

Explanation:

In the above exercise –

x = np.array(['Python', 'PHP', 'JS', 'Examples', 'html5', '5'], dtype=np.str): This statement creates a NumPy array x containing 6 strings with different characters and cases.

r1 = np.char.isdigit(x): This statement creates a boolean NumPy array r1 of the same shape as x with True where each element of x is a digit and False otherwise.

r2 = np.char.islower(x): This statement creates a boolean NumPy array r2 of the same shape as x with True where each element of x is in lowercase and False otherwise.

r3 = np.char.isupper(x): This statement creates a boolean NumPy array r3 of the same shape as x with True where each element of x is in uppercase and False otherwise.

Pictorial Presentation:

Python-Numpy Code Editor: