Python variables are very easy to set up and very flexible.

a = 10
print(a)
# 10
 
a = 2.5
print(a)
# 2.5
 
a += a
print(a)
# 5.0
 
a = [ 1, 2, 3, 4, 5 ]
print( a[2] )
# 3
 
len(a)
# 5
 
a = "hello"
a += " world"
print(a)
# hello world
 
len(a)
# 11
 
print(a[10])
# d

So we just saw here that creating a variable is just writing its name and giving it a value. The type of value does not matter. And the variable will accept any type of value even if it's different from the one it use to have before.

Commenting:

# The most common way of commenting. 
print ("hello")  # Works only for whatever is after the # tag.
# Works only on a single line
 
'''
Multi line commenting is done this way.
It's actually creating a multi-line String.
But not assigning it to any variable.
Works well if you want to comment multi lines of code.
'''