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Python String | isupper() and islower() Methods with Examples

Python String | isupper() and islower() Methods with Examples, these are the in-built methods in Python, which are used to check whether a string is in Uppercase or Lowercase.
Submitted by IncludeHelp, on July 18, 2018

isupper() and islower() both are the in- built methods in Python which works with the strings.

1) String isupper() Method

isupper() returns "true" if all characters of the string are uppercase character.

Syntax:

 String.isupper()

Parameter: None

Return type:

• true - if all characters of the string are uppercase characters.
• false - if any of the characters is not in uppercase character.

Example:

# str1 with all uppercase characters
str1 = "GOOGLE"
print str1.isupper()

# str2 with uppercase character, DOT, SPACE 
str2 = "GOOGLE.COM"
print str2.isupper()

# str3 with uppercase and lowercase characters
str3 ="GOOGLE.com"
print str3.isupper()

# str4 with all lowercase characters
str4 = "google.com"
print str4.isupper()

Output

    True
    True
    False
    False

2) String islower() Method

islower() returns "true" if all characters of the string are lowercase character.

Syntax:

 String.islower()

Parameter: None

Return type:

• true - if all characters of the string are lowercase characters.
• false - if any of the characters is not in lowercase character.

Example:

# str1 with all lowercase characters
str1 = "google"
print str1.islower()

# str2 with lowercase character, DOT, SPACE 
str2 = "google.com"
print str2.islower()

# str3 with lowercase and uppercase characters
str3 ="google.COM"
print str3.islower()

# str4 with all uppercase characters
str4 = "GOOGLE.COM"
print str4.islower()

Output

    True
    True
    False
    False