Python String isupper()

The string isupper() method returns whether or not all characters in a string are uppercased or not.

The syntax of isupper() method is:

string.isupper()

1. String isupper() Parameters

The isupper() method doesn’t take any parameters.

2. Return value from String isupper() 

The isupper() method returns:

• True if all characters in a string are uppercase characters
• False if any characters in a string are lowercase characters

3. Example 1: Return value of isupper()

# example string
string = "THIS IS GOOD!"
print(string.isupper());

# numbers in place of alphabets
string = "THIS IS ALSO G00D!"
print(string.isupper());

# lowercase string
string = "THIS IS not GOOD!"
print(string.isupper());

Output

True
True
False

4. Example 2: How to use isupper() in a program?

string = 'THIS IS GOOD'
if string.isupper() == True:
  print('Does not contain lowercase letter.')
else:
  print('Contains lowercase letter.')
  
string = 'THIS IS gOOD'
if string.isupper() == True:
  print('Does not contain lowercase letter.')
else:
  print('Contains lowercase letter.')

Output

Does not contain lowercase letter.
Contains lowercase letter.