Python string islower() method with example

Python string islower() method with example

The islower() method is a built-in string method in Python that is used to check whether all the characters in a string are lowercase. It returns True if all the characters are lowercase, and False otherwise.

Syntax:

string.islower()

How to use the islower() method:

string1 = "hello world"
print(string1.islower()) # True

string2 = "Hello world"
print(string2.islower()) # False

string3 = "123abc"
print(string3.islower()) # True

string4 = "ABC"
print(string4.islower()) # False

Example 1

Checking if a String Contains Lowercase Letters.

string1 = "Hello World"
string2 = "hello world"

if string1.islower():
  print("string1 contains only lowercase letters.")
else:
  print("string1 contains uppercase letters or a mix of uppercase and lowercase letters.")

if string2.islower():
  print("string2 contains only lowercase letters.")
else:
  print("string2 contains uppercase letters or a mix of uppercase and lowercase letters.")

Example 2

Converting a String to Lowercase.

string = "Hello World"
if string.islower():
  print("The string is already in lowercase.")
else:
  string = string.lower()
  print("Converted string:", string)

Example 3

Filtering a List of Strings.

words = ["hello", "WORLD", "Python", "news"]
lowercase_words = [word for word in words if word.islower()]

print("Lowercase words:", lowercase_words)
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