Count number of Capital Letters in a string using Python

Hello connections,

I had just started programming with python, and working on a project where specifically we need to find out the capital letters (upper case letters) from the input string provided.

I had searched the internet but can't find any in-build library related to string functions, which i can use directly for this functionality.

However, from the search i got to know that there is some isUpper() function which can be used with characters to check whether the character is in upper case or lower case, but not sure how to use it for a whole long string.

Any help will be appreciable !