what does the len function do in python
Len (programming) In Python, len() can be used to denote the length of a string:
printf format string "Printf" is the name of the most-used C output function, and stands for "print formatted". Printf format strings are complementary to scanf format strings, which provide formatted input (parsing). In both cases these provide simple functionality and fixed format compared to more sophisticated and flexible template engines or parsers, but are sufficient for many purposes.