How to convert a string to lower case in Python?

How to convert a string to lower case in Python?

For example:

"Abc" -> "abc"
"BBB" -> "bbb"
"abc" -> "abc"

You can use the string.lower() method of Python:

string.lower(s)

    Return a copy of s, but with upper case letters converted to lower case.

Example:

$ python
Python 2.7.5 (default, Apr 11 2018, 07:36:10) 
[GCC 4.8.5 20150623 (Red Hat 4.8.5-28)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> "aBd F".lower()
'abd f'
>>>