Str is stands for ??? In python

Answer 1

String

e.g.

num = 1
numberAsAString = str(num)
print(numberAsAString + "!")

The numberAsAString variable takes 1 (an integer) and converts it into "1" (a string)
In the print, I pass in the number as a string and add an exclamation point to the end of the string.

Which outputs:
1!

Answer 2

thanks @Tim