Python str() built-in function
From the Python 3 documentation
Return a string version of object. If object is not provided, returns the empty string. Otherwise, the behavior of str() depends on whether encoding or errors is given.
Introduction
The str() function in Python is a built-in function that returns a string version of an object. If no object is provided, it returns an empty string. It’s a versatile function for converting other data types to strings.
Examples
>>> # transform an integer to a string
>>> from_integer = str(29)
>>> from_integer
# '29'
>>> type(from_integer)
# <class 'str'>
>>> # transform a float to string
>>> from_float = str(-3.14)
>>> from_float
# '-3.14'
>>> type(from_float)
# <class 'str'>
>>> # return an empty string
>>> str()
# ''