The syntax of islower() is:
string.islower()
islower() parameters
The islower() method doesn't take any parameters.
Return Value from islower()
The islower() method returns:
- True if all alphabets that exist in the string are lowercase alphabets.
 - False if the string contains at least one uppercase alphabet.
 
Example 1: Return Value from islower()
s = 'this is good'
print(s.islower())
s = 'th!s is a1so g00d'
print(s.islower())
s = 'this is Not good'
print(s.islower())
Output
True True False
Example 2: How to use islower() in a program?
s = 'this is good'
if s.islower() == True:
  print('Does not contain uppercase letter.')
else:
  print('Contains uppercase letter.')
  
s = 'this is Good'
if s.islower() == True:
  print('Does not contain uppercase letter.')
else:
  print('Contains uppercase letter.')
Output
Does not contain uppercase letter. Contains uppercase letter.
Also Read: