In python, the built-in string function upper()
is used to convert a string to uppercase. It converts all lowercase characters in a string to uppercase and returns it.

s = "this is sparta!" print(s.upper())
Output:
THIS IS SPARTA!
Table of Contents
- Syntax
- Examples
- How to check if a python string is uppercase or not?
Syntax
The following is the syntax for using the string upper()
function:
string.upper()
Parameters:
The string upper function does not take any parameters.
Returns:
A string with all the cased characters converted to uppercase.
Examples
Example 1: Convert string with a mix of lowercase and uppercase characters to uppercase.
s = "tHiS iS sPArTa!" # original string print("Original String: ", s) # after converting to uppercase s_upper = s.upper() print("After Converting:", s_upper)
Output:
Original String: tHiS iS sPArTa! After Converting: THIS IS SPARTA!
In the above example, all the lowercase characters have been converted to uppercase while the uppercase characters and non-cased characters remain unchanged.
Example 2: Convert string without any alphabetical character to uppercase.
s = "123 #$% <>!?" # original string print("Original String: ", s) # after converting to uppercase s_upper = s.upper() print("After Converting:", s_upper)
Output:
Original String: 123 #$% <>!? After Converting: 123 #$% <>!?
In the above example, since the string did not have any cased characters (that is, characters associated with a case like lowercase, uppercase, or titlecase) we get the same string without any changes on applying the upper()
function.
Example 3: Using the python string uppercase function to match strings.
Often it’s required to check if two strings are the same irrespective of their case. For example, you have the names of all your leads collected via a form on your website, and it’s quite possible that many of them didn’t use a style convention like using titlecase (e.g. John Doe
), some may have filled it in all lower or all uppercase as well. In such a scenario, you can match the two strings by converting both to either upper, lower, or titlecase.
# matching strings # list of names ls = ["Bruce Banner", "peter Parkar", "STEVE RODERS"] # name to match for name = "Peter Parkar" # check whether the name is present in the list for l in ls: # match for the name if l.upper() == name.upper(): print("Match found for", name)
Output:
Match found for Peter Parkar
In the above example, we check whether a name is present in a list irrespective of the case of the strings.
How to check if a python string is uppercase or not?
We can check whether a string is uppercase or not using the isupper()
function. It’s a string function that returns True
if all the cased characters in the string are in uppercase. If the string does not contain any cased characters or any of the cased characters are not uppercase then it returns False
.
Example:
s = "THIS IS SPARTA!" print(s.isupper())
Output:
True
In the above example, since all the cased characters are in uppercase the isupper()
function returns True
.
For more, refer to python string methods docs.
Other articles on python strings:
- Python String Split – With Examples
- Python String Join – With Examples
- Python String Concatenation – With Examples
- Python String Replace – With Examples
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