questions

Regex:
how to match non empty strings between two elements?
[Python] what is difference between re.search(), re.match() and re.findall(), when to use each of them?

[Python] how to execute multiline code in the python interpreter? use backslashes to continue on the next line

[Python] how to test if a variable is empty string or contains only space or is none? if a or a.strip(), this will first test if it's None, then test if it only contains spaces, tabs, newlines and so on.

[Python] how to test if a variable is True, False, or None?
test True: if a is True
#if a is a non-zero number, a will evaluate to true, but a number is not the same as boolean True! keep in mind of this.
test None: if a is None
#None is a special singleton object, there can only be one. Just check to see if you have that object.
test False: a not True and not None, then it's

[Python] how to check if a variable is a string?
method a: isinstance(a, str)
The isinstance function takes two arguments. The first is your variable. The second is the type you want to check for. in Python 3.x, all types are classes.

method b: if type(a) == str:
use the type built-in function to see the type of variables. None:'NoneType', booleans:'bool', strings:'str', numbers:'int','float', lists:'list', tuples:'tuple', dictionaries:'dict', ...